IIT JEE Practice Question and Answer
8Q: Q's mother is sister of P and daughter of M who is brother of R. S is daughter of P and sister of T. How is M related to T ? 1622 05b5cc73de4d2b4197774f957
5b5cc73de4d2b4197774f957- 1Grand fathertrue
- 2Grand motherfalse
- 3Grand father or Grand motherfalse
- 4Can't be determinedfalse
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Answer : 1. "Grand father"
Explanation :
Answer: A) Grand father Explanation: Q's mother is sister of P and daughter of M => P is the child of M.S is daughter of P and sister of T, so P is parent of T too.M ----> parent --------> P ------------>parent -------------> TBut given M is brother of R => M is male. So, M is grandfather of T.
Q: Three taps I, J and K can fill a tank in 20,30and 40 minutes respectively. All the taps are opened simultaneously and after 5 minutes tap A was closed and then after 6 minutes tab B was closed .At the moment a leak developed which can empty the full tank in 70 minutes. What is the total time taken for the completely full ? 4217 05b5cc73de4d2b4197774f952
5b5cc73de4d2b4197774f952- 124.315 minutesfalse
- 226.166 minutestrue
- 322.154 minutesfalse
- 424 minutesfalse
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Answer : 2. "26.166 minutes"
Explanation :
Answer: B) 26.166 minutes Explanation: Upto first 5 minutes I, J and K will fill => 5[(1/20)+(1/30)+(1/40)] = 65/120 For next 6 minutes, J and K will fill => 6[(1/30)+(1/40)] = 42/120 So tank filled upto first 11 minutes = (65/120) + (42/120) = 107/120 So remaining tank = 13/120 Now at the moment filling with C and leakage @ 1/60 per minute= (1/40) - (1/70) = 3/280.So time taken to fill remaining 13/120 tank =(13/120) /(3/280) = 91/6 minutes Hence total time taken to completely fill the tank = 5 + 6 + 91/6 = 26.16 minutes.
Q: The average of the ages of Sushanth, Krish and Rishi is 43 years and the average of the ages of Sushanth, Rishi and Rohit is 49 years. If Rohit is 54 years old, what is Krish's age ? 1377 05b5cc73de4d2b4197774f948
5b5cc73de4d2b4197774f948- 134 yearsfalse
- 226 yearsfalse
- 324 yearsfalse
- 436 yearstrue
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Answer : 4. "36 years"
Explanation :
Answer: D) 36 years Explanation: Let present ages of Sushanth = w, Krish = x, Rishi = y and Rohit = z , thenw + x + y = 43 x 3 = 129 ---(i) andw + y + z = 49 x 3 = 147 ---(ii)Subtracting (i) from (ii), (w+y+z) - (w+x+y) = 147 - 129 , z - x = 18 ---(iii)Given Rohit's age=z=54, so from (iii), x = 54 - 18 = 36.Therefore, Krish age is 36 years.
Q: A can do a work in 9 days, B can do a work in 7 days, C can do a work in 5 days. A works on the first day, B works on the second day and C on the third day respectively that is they work on alternate days. When will they finish the work ? 939 05b5cc73de4d2b4197774f94d
5b5cc73de4d2b4197774f94d- 1[7 + (215/345)] daysfalse
- 2[6 + (11/215)] daysfalse
- 3[6 + (261/315)] daystrue
- 4[5 + (112/351)] daysfalse
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Answer : 3. "[6 + (261/315)] days"
Explanation :
Answer: C) [6 + (261/315)] days Explanation: After day 1, A finishes 1/9 of the work. After day 2, B finishes 1/7 more of the total work. (1/9) + (1/7) is finished. After day 3, C finishes 1/5 more of total work. Total finished is 143/315. So, after day 6, total work finished is 286/315. Now remaining work = 29 /315 On day 7, A will work again Work will be completed on day 7 when A is working. He must finish 29/315 of total remaining work. Since he takes 9 days to finish the total task, he will need 261/315 of the day. Total days required is 6 + (261/315) days.
Q: Which nation plans to build the first city on Mars by 2117 ? 1272 05b5cc73de4d2b4197774f93e
5b5cc73de4d2b4197774f93e- 1Indiafalse
- 2United Arab Emiratestrue
- 3Chinafalse
- 4Russiafalse
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Answer : 2. "United Arab Emirates"
Explanation :
Answer: B) United Arab Emirates Explanation: The President and Vice-President of United Arab Emirates Sheik Mohamed bin Zayed Al Nahyan and Shaik Mohammed bin Rashid Al Maktoum announced in Febraury 2017 that they are planning to build the first inhabitable human settlement on Mars by 2117.
Q: In a mixture of milk and water the proportion of water by weight was 75%. If in 60 gm of mixture 15 gm water was added, what would be the percentage of water ? (Weight in gm) 1172 05b5cc73de4d2b4197774f943
5b5cc73de4d2b4197774f943- 180%true
- 270%false
- 375%false
- 462%false
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Answer : 1. "80%"
Explanation :
Answer: A) 80% Explanation: Water in 60 gm mixture=60 x 75/100 = 45 gm. and Milk = 15 gm. After adding 15 gm. of water in mixture, total water = 45 + 15 = 60 gm and weight of a mixture = 60 + 15 = 75 gm. So % of water = 100 x 60/75 = 80%.
Q: The payment per hour for a daily-wages employee is increased by 33.33 and the working time is reduced by 33.33%. What is the percentage change in the employee's income ? 1270 05b5cc73de4d2b4197774f934
5b5cc73de4d2b4197774f934- 111.11% decreasetrue
- 221.11% increasefalse
- 311.11% increasefalse
- 421.11% decreasefalse
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Answer : 1. "11.11% decrease"
Explanation :
Answer: A) 11.11% decrease Explanation: If earlier he is getting Rs. 1 per hr and working for 1 hr, income = Rs. 1Now he is getting Rs 1.3333 per hr and working for 0.66667 hrs Then income for 0.66667 hrs = Rs. 0.8889. If payment per hr is increased by 33.33 % and working hours dereased by 33.33%, then 11.11 % decrease in income.
Q: A farmer divides his herd of k cows among his 4 sons, so that one son gets one half of the herd, the second gets one-fourth, the third gets one-fifth and the fourth gets 9 cows. Then k is equal to ? 1136 05b5cc73de4d2b4197774f92a
5b5cc73de4d2b4197774f92a- 1160false
- 2120false
- 3140false
- 4180true
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Answer : 4. "180"
Explanation :
Answer: D) 180 Explanation: Given total number of cows = kNow, 1st son share = k/22nd son share = k/43rd son share = k/54th son share = 9 (k) + (k/4) + (k/5) + 9 = k=> k - (19k/20) = 9=> (20k-19k)/20 = 9=> k = 180.