IIT JEE Practice Question and Answer
8Q: In a G - 20 meeting there were total 20 people representing their own country. All the representative sat around a circular table. Find the number of ways in which we can arrange them around a circular table so that there is exactly one person between two representatives namely Manmohan and Musharraf. 3402 05b5cc7d1e4d2b4197775128b
5b5cc7d1e4d2b4197775128b- 12 x (17!)false
- 22 x (18!)true
- 3(3!) x (18!)false
- 4(17!)false
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Answer : 2. "2 x (18!)"
Explanation :
Answer: B) 2 x (18!) Explanation: A person can be chosen out of 18 people in 18 ways to be seated between Musharraf and Manmohan. Now consider Musharraf, Manmohan, and the third person, sitting between them, as a single personality, we can arrange them in 17! ways but Musharraf and Manmohan can also be arranged in 2 ways. Required number of permutations = 18 x (17!) x 2 = 2 x 18!
Q: Mother’s age today is thrice as her daughter’s. After 10 years it would be just double. How old is the daughter today ? 3391 05b5cc75ee4d2b4197774fcde
5b5cc75ee4d2b4197774fcde- 18 yearsfalse
- 29 yearsfalse
- 310 yearstrue
- 411 yearsfalse
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Answer : 3. "10 years"
Explanation :
Answer: C) 10 years Explanation: Let the age of the daughter today be ‘x’ years. Mother’s age today = 3x years After 10 years, we have 3x + 10 = 2(x + 10) x = 10 years.
Q: In what way does ocean water move globally? 3388 05b5cc672e4d2b4197774c082
5b5cc672e4d2b4197774c082- 1Along cold water currents from the equator to the poles.false
- 2Along warm water currents from the warmer regions to colder regionsfalse
- 3Along warm water currents from the equator to the polestrue
- 4None of the abovefalse
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Answer : 3. "Along warm water currents from the equator to the poles"
Explanation :
Answer: C) Along warm water currents from the equator to the poles Explanation:
Q: The average weight of a group of boys is 30 kg. After a boy of weight 35 kg joins the group, the average weight of the group goes up by 1 kg. Find the number of boys in the group originally ? 3384 05b5cc6ebe4d2b4197774ee6e
5b5cc6ebe4d2b4197774ee6e- 16false
- 28false
- 34true
- 45false
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Answer : 3. "4"
Explanation :
Answer: C) 4 Explanation: Let the number of boys in the group originally be x.Total weight of the boys = 30xAfter the boy weighing 35 kg joins the group, total weight of boys = 30x + 35So 30x + 35 + 31(x + 1) = > x = 4.
Q: 96% of the population of a village is 23040. The total population of the village is ? 3382 05b5cc6e7e4d2b4197774ed92
5b5cc6e7e4d2b4197774ed92- 124000true
- 232256false
- 325478false
- 426587false
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Answer : 1. "24000"
Explanation :
Answer: A) 24000 Explanation: Let the total population be 'P' P x (96/100) = 23040 P = 240 * 100 P = 24000.
Q: Find the odd one out of the following number series? 9 5 6 14 56 488 3377 05b5cc66de4d2b4197774bfb0
5b5cc66de4d2b4197774bfb0- 156true
- 26false
- 314false
- 45false
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Answer : 1. "56"
Explanation :
Answer: A) 56 Explanation: The given number series follows a pattern that, 9 9 x 0.5 + 0.5 = 5 5 x 1 + 1 = 6 6 x 2 + 2 = 14 14 x 4 + 4 = 60 (not equals to 56) 60 x 8 + 8 = 488. Hence, the odd one in the given number series is 56.
Q: Equal quantities of three mixtures of milk and water are mixed in the ratio 1:2, 2:3 and 3:4. The ratio of water and milk in the mixture is ? 3375 05b5cc73ae4d2b4197774f8c9
5b5cc73ae4d2b4197774f8c9- 1193 : 122true
- 297 : 102false
- 3115 : 201false
- 4147 : 185false
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Answer : 1. "193 : 122"
Explanation :
Answer: A) 193 : 122 Explanation: Given the three mixtures ratio as (1:2),(2:3),(3:4) (1+2),(2+3),(3+4) Total content = 3,5,7 Given equal quantities of the three mixtures are mixed, then LCM of 3, 5, 7 = 105 105/3 = 35 , 105/5 = 21 , 105/7 = 15 Now, the individual equal quantity ratios are (35x1, 35x2), (21x2, 21x3), (15x3, 15x4) i.e (35,70), (42,63), (45,60) So overall mixture ratio of milk and water is 35+42+45 : 70+63+60 122:193 But in the question asked the ratio of water to milk = 193 : 122
Q: P and Q were assigned to do a work for an amount of 1200. P alone can do it in 15 days while Q can do it in 12 days. With the help of R they finish the work in 6 days. Find the share of R ? 3373 05b5cc731e4d2b4197774f814
5b5cc731e4d2b4197774f814- 1120true
- 2240false
- 3360false
- 4180false
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Answer : 1. "120"
Explanation :
Answer: A) 120 Explanation: 1/15 + 1/12 + 1/R = 1/6, we got R = 60 (it means R will take 60 days to complete the work alone) so ratio of work done by P:Q:R = 1/15 : 1/12 : 1/60 = 5 : 4 : 1 so R share = (1/10) x 1200 = 120.

