GATE 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. 3485 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: 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 ? 3460 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: _ tu _ rt _ s _ _ usrtu _ 3460 05b5cc6d9e4d2b4197774e843
5b5cc6d9e4d2b4197774e843- 1rsutrrfalse
- 2rsurtrfalse
- 3rsurtstrue
- 4rtusrufalse
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Answer : 3. "rsurts"
Explanation :
Answer: C) rsurts Explanation: The series rtus/rtus/rtus/rtus. Thus, the pattern 'rtus' is repeated.
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 ? 3452 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: Find the next number in the given number series? 50, 51, 47, 56, 40, ? 3451 05b5cc669e4d2b4197774bf52
5b5cc669e4d2b4197774bf52- 158false
- 265true
- 376false
- 481false
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Answer : 2. "65"
Explanation :
Answer: B) 65 Explanation: The given number series is 50, 51, 47, 56, 40, ? 5050 + 12 = 5151 - 22 = 4747 + 32 = 5656 - 42 = 4040 + 52 = 65 Hence, the next number in the given number series is 65.
Q: 96% of the population of a village is 23040. The total population of the village is ? 3439 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: fifteen persons are sitting around a circular table facing the centre. What is the probability that three particular persons sit together ? 3434 05b5cc731e4d2b4197774f7dd
5b5cc731e4d2b4197774f7dd- 13/91true
- 22/73false
- 31/91false
- 43/73false
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Answer : 1. "3/91"
Explanation :
Answer: A) 3/91 Explanation: In a circle of n different persons, the total number of arrangements possible = (n - 1)!Total number of arrangements = n(S) = (15 – 1)! = 14 !Taking three persons as a unit, total persons = 13 (in 4 units)Therefore no. of ways for these 13 persons to around the circular table = (13 - 1)! = 12!In any given unit, 3 particular person can sit in 3!. Hence total number of ways that any three person can sit =n(E) = 12! X 3!Therefore P (E) = probability of three persons sitting together = n(E) / n(S) = 12! X 3 ! / 14!= 12!x3x2 / 14x13x12! = 6/14x13 = 3/91
Q: A large tanker can be filled by two pipes A and B in 60 and 40 minutes respectively. How many minutes will it take to fill the tanker from empty state if B is used for half the time and A and B fill it together for the other half ? 3431 05b5cc6dce4d2b4197774e9ab
5b5cc6dce4d2b4197774e9ab- 131 minfalse
- 229 minfalse
- 328 minfalse
- 430 mintrue
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Answer : 4. "30 min"
Explanation :
Answer: D) 30 min Explanation: Part filled by (A + B) in 1 minute = (1/60 + 1/40) = 1/24Suppose the tank is filled in x minutes.Then, x/2(1/24 + 1/40) = 1(x/2) * (1/15) = 1 => x = 30 min.

