IIT JEE Practice Question and Answer
8Q: If two cards are taken one after another without replacing from a pack of 52 cards. What is the probability for the two cards be Ace ? 1269 05b5cc74ae4d2b4197774fa81
5b5cc74ae4d2b4197774fa81- 151/1221false
- 242/221false
- 31/221true
- 452/1245false
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Answer : 3. "1/221"
Explanation :
Answer: C) 1/221 Explanation: Total Combination of getting a card from 52 cards = C152 Because there is no replacement, so number of cards after getting first card= 51 Now, Combination of getting an another card= C151 Total combination of getting 2 cards from 52 cards without replacement= (C152×C151) There are total 4 Ace in stack. Combination of getting 1 Ace is = C14 Because there is no replacement, So number of cards after getting first Ace = 3 Combination of getting an another Ace = C13 Total Combination of getting 2 Ace without replacement=C14×C13 Now,Probability of getting 2 cards which are Ace =C14×C13C152×C151 = 1/221.
Q: At the university entrance exam, a candidate is admitted according to whether he has passed or failed the test. Of the candidates who are really capable, 80 % pass the test and of the incapable, 30 % pass the test. Given that 40 % of the candidates are really capable, then the proportion of the really capable students who can pass the test to the total students who can pass is about ? 3406 05b5cc74ae4d2b4197774fa77
5b5cc74ae4d2b4197774fa77- 111/24false
- 21/5false
- 316/25true
- 46/5false
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Answer : 3. "16/25"
Explanation :
Answer: C) 16/25 Explanation: If there are total 100 candidates, 40 candidates are really capable and 60 candidates are incapable.Of the candidates who are really capable = 80% 40*(80/100)=32 pass the test andof the incapable= 30%60*(30/100)=18 pass the test.Total candidates who passed the test = 32+18 = 50The proportion of the really capable students who can pass the test to the total students who can pass = 32/50 = 16/25.
Q: What is the next letter in the given seriesM N J Q G ? 1029 05b5cc74ae4d2b4197774fa7c
5b5cc74ae4d2b4197774fa7c- 1Ufalse
- 2Sfalse
- 3Ttrue
- 4Hfalse
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Answer : 3. "T"
Explanation :
Answer: C) T Explanation: 1ST SERIES = M J G... It decreasing by 3 alphabets.2ND SERIES = N Q... It increasing by 3 alphabets. M N J Q G T...
Q: A seller uses 840 gm in place of 1 kg to sell his goods. Find his actual profit/loss % When he sells his article on 4% loss on cost price ? 1526 15b5cc74ae4d2b4197774fa72
5b5cc74ae4d2b4197774fa72- 114.28 % profittrue
- 224.18 % profitfalse
- 314.28 % lossfalse
- 424.18 % lossfalse
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Answer : 1. "14.28 % profit"
Explanation :
Answer: A) 14.28 % profit Explanation: Let 1kg of Rs. 100 then 840gm is of Rs. 84.Now (label on can 1kg but contains 840kg ) so for customer it is of Rs. 100 and further gives 4% discount [he sells his article on 4% loss on cost price.] So now S.P = Rs. 96But actually it contains 840 gm so C.P for shopkeeper = Rs. 84S.P = Rs. 96C.P = Rs. 84Profit% = {(S.P-C.P)/C.P}x100{(96-84)/84} x 100 = 14.28571429% PROFIT.
Q: When Raj Tarun was born, his father was 32 years older than his brother and his mother was 25 years older than his sister. If Raj Tarun's brother is 6 years older than Raj Tarun and his mother is 3 years younger than his father, how old was Raj Tarun's sister when Raj Tarun was born ? 2251 05b5cc74ae4d2b4197774fa6d
5b5cc74ae4d2b4197774fa6d- 15false
- 210true
- 315false
- 48false
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Answer : 2. "10"
Explanation :
Answer: B) 10 Explanation: Raj Tarun's age = 0 when he was born.Then, given his brother is 6 years old.Then his father is 6 + 32 = 38 when Raj Tarun was bornAnd his mother is 3 years yonger than his father => so his mother was 35 years old when Raj Tarun was bornand his sister is 25 year younger than his mother so Raj Tarun's sister was 10 years old when Raj Tarun was born.
Q: A man reaches his office 20 min late, if he walks from his home at 3 km per hour and reaches 30 min early if he walks 4 km per hour. How far is his office from his house ? 4954 05b5cc74ae4d2b4197774fa68
5b5cc74ae4d2b4197774fa68- 120 kmfalse
- 216 kmfalse
- 314 kmfalse
- 410 kmtrue
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Answer : 4. "10 km"
Explanation :
Answer: D) 10 km Explanation: Let distance = x km.Time taken at 3 kmph : dist/speed = x/3 = 20 min late.time taken at 4 kmph : x/4 = 30 min earlierdifference between time taken : 30-(-20) = 50 mins = 50/60 hours.x/3- x/4 = 50/60x/12 = 5/6x = 10 km.
Q: Two trains namely X & Y leave station 'A' at 6.30am and 7.40am and travel at 30km/hr and 40 km/hr respectively. How many kms from 'A' will the trains meet ? 4455 05b5cc745e4d2b4197774fa5e
5b5cc745e4d2b4197774fa5e- 1140 kmstrue
- 2120 kmsfalse
- 396 kmsfalse
- 4142 kmsfalse
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Answer : 1. "140 kms"
Explanation :
Answer: A) 140 kms Explanation: It is given train X leave station A at 6:30 am, here it is asked to calculate the distance from A when the trains meet, theDistance traveled by train left at 6:30 am upto 7:40 am i.e. in 1 hr. 10 min. or 7/6 hours = 30 x 7/6 = 35 kmSo train leaving at 7:40 am will meet first train after covering a distance of 35 km. with relative speed of 40-30=10 km/hr.Hence time taken = 35/10 = 3.5 hours or 3 hours 30 minutesSo distance from A = Distance traveled by 2nd train in 3 hr. 30 min = 40 x 3.5 = 140 km.
Q: Arrange the following words in an appropriate order 1. Rainbow 2. Rain 3. Sun 4. Happy 5. Child 1434 05b5cc745e4d2b4197774fa59
5b5cc745e4d2b4197774fa59- 14, 2, 3, 5, 1false
- 24, 5, 1, 2, 3false
- 32, 1, 4, 5, 3false
- 42, 3, 1, 5, 4true
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Answer : 4. "2, 3, 1, 5, 4"
Explanation :
Answer: D) 2, 3, 1, 5, 4 Explanation: Firstly Rain falls and then Sun comes and Rainbow forms. After that Child sees the rainbow and feels Happy.