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प्र: A, B and C can do a piece of work in 72, 48 and 36 days respectively. For first p/2 days, A & B work together and for next ((p+6))/3days all three worked together. Remaining 125/3% of work is completed by D in 10 days. If C & D worked together for p day then, what portion of work will be remained? 1672 0

उत्तर : 2. "1/6"
व्याख्या :
Answer: B) 1/6 Explanation: Total work is given by L.C.M of 72, 48, 36 Total work = 144 units Efficieny of A = 144/72 = 2 units/day Efficieny of B = 144/48 = 3 units/day Efficieny of C = 144/36 = 4 units/day According to the given data, 2 x p/2 + 3 x p/2 + 2 x (p+6)/3 + 3 x (p+6)/3 + 4 x (p+6)/3 = 144 x (100 - 125/3) x 1/100 3p + 4.5p + 2p + 3p + 4p = 84 x 3 - 54 p = 198/16.5 p = 12 days. Now, efficency of D = (144 x 125/3 x 1/100)/10 = 6 unit/day (C+D) in p days = (4 + 6) x 12 = 120 unit Remained part of work = (144-120)/144 = 1/6.

प्र: The ratio of speeds of a car, a train and a bus is 5:9:4. The average speed of the car, the bus and the train is 72 km/hr together. What is the average speed of the car and the train together ? 1668 0

उत्तर : 1. "84 km/hr"
व्याख्या :
Answer: A) 84 km/hr Explanation: Let the speeds of the car, train and bus be 5x, 9x and 4x km/hr respectively.Average speed = 5x + 9x + 4x/3 = 18x /3 = 6x km/hr.Also, 6x = 72 => x = 12 km/hrTherefore, the average speed of the car and train together is = 5x+9x2= 7x = 7 x 12 = 84 km/hr.

प्र: 14 persons are seated around a circular table. Find the probability that 3 particular persons always seated together. 1668 0

उत्तर : 3. "24/625"
व्याख्या :
Answer: C) 24/625 Explanation: Total no of ways = (14 – 1)! = 13! Number of favorable ways = (12 – 1)! = 11! So, required probability = 11!×3!13! = 39916800×66227020800 = 24625

प्र: Population of a colony of mosquitoes is increasing by 20% per day. If the population on Monday was 3000, on which day of that week the population would be 5184 ? 1665 0

उत्तर : 1. "Thursday"
व्याख्या :
Answer: A) Thursday Explanation: Given monday population = 3000Per day 20% increase in population. Tuesday population = 3000 + 3000x20/100 = 3000 + 600 = 3600 Wednesday population =3600 + 3600x20/100 = 3600 + 720 = 4320 Thursday population = 4320 + 4320x20/100 = 4320 + 864 = 5184 So that day is Thursday.

प्र: In a group of 6 boys and 4 girls, four children are to be selected. In how many different ways can they be selected such that at least one boy should be there ? 1664 0

उत्तर : 3. "209"
व्याख्या :
Answer: C) 209 Explanation: We may have (1 boy and 3 girls)or(2boys and 2 girls)or(3 boys and 1 girl)or(4 boys). Required number of ways = (C16× C34) + C26×C24 + (C36× C14) + (C46) = (24+90+80+15) = 209.

प्र: On a school’s Annual day sweets were to be equally distributed amongst 112 children. But on that particular day, 32 children were absent. Thus the remaining children got 6 extra sweets. How many sweets was each child originally supposed to get ? 1662 0

उत्तर : 4. "15"
व्याख्या :
Answer: D) 15 Explanation: Let 'K' be the total number of sweets.Given total number of students = 112If sweets are distributed among 112 children,Let number of sweets each student gets = 'L' => K/112 = L ....(1)But on that day students absent = 32 => remaining = 112 - 32 = 80Then, each student gets '6' sweets extra. => K/80 = L + 6 ....(2)from (1) K = 112L substitute in (2), we get112L = 80L + 48032L = 480L = 15 Therefore, 15 sweets were each student originally supposed to get.

प्र: (3x + 2) (2x - 5) = ax² + kx + n. What is the value of a - n + k ? 1661 0

उत्तर : 3. "5"
व्याख्या :
Answer: C) 5 Explanation: (3x + 2) (2x - 5) = ax2+kx+n ...............(1) But (3x + 2)(2x - 5) = 6x2-11x-10........(2) so by comparing (1) & (2), we get a= 6, k= -11 , n= -10 (a - n + k) = 6 + 10 - 11 = 5.

प्र: In a certain Business, the profit is 220% of the cost. If the cost increases by 25% but the selling price remains constant, approximately what percentage of the selling price is the profit ? 1660 0

उत्तर : 1. "61%"
व्याख्या :
Answer: A) 61% Explanation: Let C.P.= Rs. 100. Then, Profit = Rs.220, S.P. = Rs.320. New C.P. = 125% of Rs. 100 = Rs. 125 New S.P. = Rs.320. Profit = Rs. (320 - 125) = Rs. 195 Required percentage = 195320×100== 60.9 =~ 61%

प्र: The ratio of speeds of a car, a train and a bus is 5:9:4. The average speed of the car, the bus and the train is 72 km/hr together. What is the average speed of the car and the train together ? 1668 0

प्र: 14 persons are seated around a circular table. Find the probability that 3 particular persons always seated together. 1668 0

उत्तर : 3. "24/625"
व्याख्या :
Answer: C) 24/625 Explanation: Total no of ways = (14 – 1)! = 13! Number of favorable ways = (12 – 1)! = 11! So, required probability = 11!×3!13! = 39916800×66227020800 = 24625

प्र: Population of a colony of mosquitoes is increasing by 20% per day. If the population on Monday was 3000, on which day of that week the population would be 5184 ? 1665 0

प्र: In a group of 6 boys and 4 girls, four children are to be selected. In how many different ways can they be selected such that at least one boy should be there ? 1664 0

उत्तर : 3. "209"
व्याख्या :
Answer: C) 209 Explanation: We may have (1 boy and 3 girls)or(2boys and 2 girls)or(3 boys and 1 girl)or(4 boys). Required number of ways = (C16× C34) + C26×C24 + (C36× C14) + (C46) = (24+90+80+15) = 209.

प्र: On a school’s Annual day sweets were to be equally distributed amongst 112 children. But on that particular day, 32 children were absent. Thus the remaining children got 6 extra sweets. How many sweets was each child originally supposed to get ? 1662 0

प्र: (3x + 2) (2x - 5) = ax² + kx + n. What is the value of a - n + k ? 1661 0

उत्तर : 3. "5"
व्याख्या :
Answer: C) 5 Explanation: (3x + 2) (2x - 5) = ax2+kx+n ...............(1) But (3x + 2)(2x - 5) = 6x2-11x-10........(2) so by comparing (1) & (2), we get a= 6, k= -11 , n= -10 (a - n + k) = 6 + 10 - 11 = 5.

प्र: In a certain Business, the profit is 220% of the cost. If the cost increases by 25% but the selling price remains constant, approximately what percentage of the selling price is the profit ? 1660 0

उत्तर : 1. "61%"
व्याख्या :
Answer: A) 61% Explanation: Let C.P.= Rs. 100. Then, Profit = Rs.220, S.P. = Rs.320. New C.P. = 125% of Rs. 100 = Rs. 125 New S.P. = Rs.320. Profit = Rs. (320 - 125) = Rs. 195 Required percentage = 195320×100== 60.9 =~ 61%

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प्र: The ratio of speeds of a car, a train and a bus is 5:9:4. The average speed of the car, the bus and the train is 72 km/hr together. What is the average speed of the car and the train together ? 1668 05b5cc736e4d2b4197774f83c

प्र: 14 persons are seated around a circular table. Find the probability that 3 particular persons always seated together. 1668 05b5cc6b6e4d2b4197774d5b8

उत्तर : 3. "24/625" व्याख्या :Answer: C) 24/625 Explanation: Total no of ways = (14 – 1)! = 13! Number of favorable ways = (12 – 1)! = 11! So, required probability = 11!×3!13! = 39916800×66227020800 = 24625

प्र: Population of a colony of mosquitoes is increasing by 20% per day. If the population on Monday was 3000, on which day of that week the population would be 5184 ? 1665 05b5cc73ae4d2b4197774f8f1

प्र: In a group of 6 boys and 4 girls, four children are to be selected. In how many different ways can they be selected such that at least one boy should be there ? 1664 05b5cc774e4d2b41977750011

उत्तर : 3. "209" व्याख्या :Answer: C) 209 Explanation: We may have (1 boy and 3 girls)or(2boys and 2 girls)or(3 boys and 1 girl)or(4 boys). Required number of ways = (C16× C34) + C26×C24 + (C36× C14) + (C46) = (24+90+80+15) = 209.

प्र: On a school’s Annual day sweets were to be equally distributed amongst 112 children. But on that particular day, 32 children were absent. Thus the remaining children got 6 extra sweets. How many sweets was each child originally supposed to get ? 1662 05b5cc741e4d2b4197774f9a4

प्र: (3x + 2) (2x - 5) = ax² + kx + n. What is the value of a - n + k ? 1661 05b5cc74fe4d2b4197774fafe

उत्तर : 3. "5" व्याख्या :Answer: C) 5 Explanation: (3x + 2) (2x - 5) = ax2+kx+n ...............(1) But (3x + 2)(2x - 5) = 6x2-11x-10........(2) so by comparing (1) & (2), we get a= 6, k= -11 , n= -10 (a - n + k) = 6 + 10 - 11 = 5.

प्र: In a certain Business, the profit is 220% of the cost. If the cost increases by 25% but the selling price remains constant, approximately what percentage of the selling price is the profit ? 1660 05b5cc767e4d2b4197774fe45

उत्तर : 1. "61%" व्याख्या :Answer: A) 61% Explanation: Let C.P.= Rs. 100. Then, Profit = Rs.220, S.P. = Rs.320. New C.P. = 125% of Rs. 100 = Rs. 125 New S.P. = Rs.320. Profit = Rs. (320 - 125) = Rs. 195 Required percentage = 195320×100== 60.9 =~ 61%

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प्र: The ratio of speeds of a car, a train and a bus is 5:9:4. The average speed of the car, the bus and the train is 72 km/hr together. What is the average speed of the car and the train together ? 1668 0

प्र: 14 persons are seated around a circular table. Find the probability that 3 particular persons always seated together. 1668 0

उत्तर : 3. "24/625"
व्याख्या :
Answer: C) 24/625 Explanation: Total no of ways = (14 – 1)! = 13! Number of favorable ways = (12 – 1)! = 11! So, required probability = 11!×3!13! = 39916800×66227020800 = 24625

प्र: Population of a colony of mosquitoes is increasing by 20% per day. If the population on Monday was 3000, on which day of that week the population would be 5184 ? 1665 0

प्र: In a group of 6 boys and 4 girls, four children are to be selected. In how many different ways can they be selected such that at least one boy should be there ? 1664 0

उत्तर : 3. "209"
व्याख्या :
Answer: C) 209 Explanation: We may have (1 boy and 3 girls)or(2boys and 2 girls)or(3 boys and 1 girl)or(4 boys). Required number of ways = (C16× C34) + C26×C24 + (C36× C14) + (C46) = (24+90+80+15) = 209.

प्र: On a school’s Annual day sweets were to be equally distributed amongst 112 children. But on that particular day, 32 children were absent. Thus the remaining children got 6 extra sweets. How many sweets was each child originally supposed to get ? 1662 0

प्र: (3x + 2) (2x - 5) = ax² + kx + n. What is the value of a - n + k ? 1661 0

उत्तर : 3. "5"
व्याख्या :
Answer: C) 5 Explanation: (3x + 2) (2x - 5) = ax2+kx+n ...............(1) But (3x + 2)(2x - 5) = 6x2-11x-10........(2) so by comparing (1) & (2), we get a= 6, k= -11 , n= -10 (a - n + k) = 6 + 10 - 11 = 5.

प्र: In a certain Business, the profit is 220% of the cost. If the cost increases by 25% but the selling price remains constant, approximately what percentage of the selling price is the profit ? 1660 0

उत्तर : 1. "61%"
व्याख्या :
Answer: A) 61% Explanation: Let C.P.= Rs. 100. Then, Profit = Rs.220, S.P. = Rs.320. New C.P. = 125% of Rs. 100 = Rs. 125 New S.P. = Rs.320. Profit = Rs. (320 - 125) = Rs. 195 Required percentage = 195320×100== 60.9 =~ 61%