IIT JEE Practice Question and Answer
8Q: Find the wrong number from the following series ?7 18 40 106 183 282 403 4830 05b5cc736e4d2b4197774f846
5b5cc736e4d2b4197774f846- 118false
- 2183false
- 340true
- 4106false
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Answer : 3. "40"
Explanation :
Answer: C) 40 Explanation: The given series follows the rule,+(11x1), +(11x3), +(11x5), +(11x7), +(11x9),.... So starting from 7, 7 + 11 = 18, 18 + 33 = 51, 51 + 55 = 106, ...So wrong number is 40 which is to be 51.
Q: 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 ? 1542 05b5cc736e4d2b4197774f83c
5b5cc736e4d2b4197774f83c- 184 km/hrtrue
- 296 km/hrfalse
- 372 km/hrfalse
- 460 km/hrfalse
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Answer : 1. "84 km/hr"
Explanation :
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.
Q: Find the wrong number from the following series ?37 47 52 67 87 112 142 5681 05b5cc736e4d2b4197774f837
5b5cc736e4d2b4197774f837- 187false
- 247true
- 352false
- 467false
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Answer : 2. "47"
Explanation :
Answer: B) 47 Explanation: The given series follows the rule,+(5x1), +(5x2), +(5x3), +(5x4), +(5x5),.... So starting from 37, 37 + 5 = 42, 42 + 10 = 52, 52 + 15 = 67, 67 + 20 = 87,...So wrong number is 47 which is to be 42.
Q: Rajitha's present age is three years less than twice her age 12 years ago. Also, the ratio of Raj's present age to Rajitha's present age is 4:9. What will be Raj's age after 5 years ? 1712 05b5cc736e4d2b4197774f82d
5b5cc736e4d2b4197774f82d- 117 yrstrue
- 216 yrsfalse
- 319 yrsfalse
- 421 yrsfalse
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Answer : 1. "17 yrs"
Explanation :
Answer: A) 17 yrs Explanation: Let the present age of Raj and Rajitha be 4x and 9x.Then, according to question,9x = 2(9x-12)-3 => 9x = 27 => x = 3Raj's present age = 4x = 12yrs, After 5 years Raj's age will be 12 + 5 = 17 yrs.
Q: Find the number of factors of 9321 ? 3117 05b5cc736e4d2b4197774f832
5b5cc736e4d2b4197774f832- 14false
- 25false
- 37false
- 48true
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Answer : 4. "8"
Explanation :
Answer: D) 8 Explanation: 9321 = 3 x 13 x 239 = 31 x 13 1 x 239 1 ; add one to all the powers ie., (1+1) x (1+1) x (1+1)= 8 ; we get eight factors.
Q: One-quarter of one-seventh of a land is sold for Rs. 30,000. What is the value of an four fifteenth of land ? 4987 05b5cc736e4d2b4197774f828
5b5cc736e4d2b4197774f828- 1Rs.1,92,000false
- 2Rs.2,24,000true
- 3Rs.1,26,000false
- 4Rs.3,42,000false
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Answer : 2. "Rs.2,24,000"
Explanation :
Answer: B) Rs.2,24,000 Explanation: One-quarter of one-seventh = 1/4 x 1/7= 1/28Now, 1/28 of a land costs = Rs. 30,000Thus, 8/35 of the land will cost = 30,000 x 28 x 4/15= Rs. 2,24,000.
Q: What is the right most integer of the expression 65776759 + 54697467 ? 9965 05b5cc731e4d2b4197774f81e
5b5cc731e4d2b4197774f81e- 14false
- 26false
- 39true
- 40false
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Answer : 3. "9"
Explanation :
Answer: C) 9 Explanation: Last digit for the power of 6 is 6 (always) Power cycle of 7 is 7, 9, 3, 1. Now 467/4 gives a remainder of 3 Then the last digit is 73 = 3 Last digit is 6 + 3 = 9.
Q: The length of a rope in meter by which a cow must be tethered in order that she may be able to graze an area of 2826 sq.m is ? 1107 05b5cc731e4d2b4197774f823
5b5cc731e4d2b4197774f823- 115 mtsfalse
- 230 mtstrue
- 324 mtsfalse
- 436 mtsfalse
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Answer : 2. "30 mts"
Explanation :
Answer: B) 30 mts Explanation: The cow can graze an area of 2826 sq.m i.e it is able to cover area of circle of 2826 sq.m Therefore, πr2 =2826r2 =(2826×7/22) = 899.18 = 900r = 30 m. Therefore, the radius of the circle implies the length of the rope = 30 mts.