IIT JEE Practice Question and Answer
8Q: If 5 men and 2 boys working together, can do four times as much work per hour as a man and a boy together. Find the ratio of the work done by a man and that of a boy for a given time ? 1513 05b5cc6e2e4d2b4197774ec4d
5b5cc6e2e4d2b4197774ec4d- 11:2false
- 21:3false
- 33:1false
- 42:1true
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Answer : 4. "2:1"
Explanation :
Answer: D) 2:1 Explanation: 5M + 2B = 4(1M + 1B) 5M + 2B = 4M + 4B 1M = 2B The required ratio of work done by a man and a boy = 2:1
Q: Find the number which multiplied by 15 is increased by 56 ? 1913 05b5cc6e2e4d2b4197774ec43
5b5cc6e2e4d2b4197774ec43- 16false
- 24true
- 33false
- 412false
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Answer : 2. "4"
Explanation :
Answer: B) 4 Explanation: Let the number be x. Then, 15x - x = 56 x = 4
Q: The number of ways in which six boys and six girls can be seated in a row for a photograph so that no two girls sit together is ? 1818 05b5cc6e2e4d2b4197774ec3e
5b5cc6e2e4d2b4197774ec3e- 12(6!)false
- 26! x 7false
- 36! x ⁷P₆true
- 4Nonefalse
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Answer : 3. "6! x ⁷P₆"
Explanation :
Answer: C) 6! x ⁷P₆ Explanation: We can initially arrange the six boys in 6! ways.Having done this, now three are seven places and six girls to be arranged. This can be done in ⁷P₆ ways. Hence required number of ways = 6! x ⁷P₆
Q: In an election only two candidates contested. A candidate secured 70% of the valid votes and won by a majority of 172 votes. Find the total number of valid votes ? 4055 05b5cc6e2e4d2b4197774ec34
5b5cc6e2e4d2b4197774ec34- 1446false
- 2415false
- 3404false
- 4430true
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Answer : 4. "430"
Explanation :
Answer: D) 430 Explanation: Let the total number of valid votes be 'V'. 70% of V = 70/100 x V = 7V/10 Number of votes secured by the other candidate = V - 7V/100 = 3V/10 Given, 7V/10 - 3V/10 = 172 => 4V/10 = 172 => 4V = 1720 => V = 430.
Q: A certain sum is invested at simple interest at 18% p.a. for two years instead of investing at 12% p.a. for the same time period. Therefore the interest received is more by Rs. 840. Find the sum ? 1256 05b5cc6e2e4d2b4197774ec39
5b5cc6e2e4d2b4197774ec39- 1Rs. 5858false
- 2Rs. 8800false
- 3Rs. 7000true
- 4Rs. 6350false
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Answer : 3. "Rs. 7000"
Explanation :
Answer: C) Rs. 7000 Explanation: Let the sum be Rs. S.(S x 18 x 2)/100 - (S x 12 x 2)/100 = 840 => 36S/100 - 24S/100 = 840 => 12S/100 = 840 => S = 7000.
Q: How much time will a train of length 200 m moving at a speed of 72 kmph take to cross another train of length 300 m, moving at 36 kmph in the same direction ? 1544 05b5cc6e2e4d2b4197774ec2f
5b5cc6e2e4d2b4197774ec2f- 158 secfalse
- 262 secfalse
- 360 secfalse
- 450 sectrue
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Answer : 4. "50 sec"
Explanation :
Answer: D) 50 sec Explanation: The distance to be covered = Sum of their lengths = 200 + 300 = 500 m. Relative speed = 72 -36 = 36 kmph = 36 x 5/18 = 10 mps. Time required = d/s = 500/10 = 50 sec.
Q: A shopkeeper sells two articles at Rs.1000 each, making a profit of 30% on the first article and a loss of 20% on the second article. Find the net profit or loss that he makes ? 1667 05b5cc6e2e4d2b4197774ec20
5b5cc6e2e4d2b4197774ec20- 10.85 %false
- 20.95 %true
- 31.0 %false
- 41.3 %false
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Answer : 2. "0.95 %"
Explanation :
Answer: B) 0.95 % Explanation: SP of first article = 1000Profit = 30%CP = (SP)x[100/(100+P)] = 10000/13 SP of second article = 1000Loss = 20%CP = (SP)x[100/(100-L)] = 5000/4 = 1250 Total SP = 2000 Total CP = 10000/13 + 1250 = 2019.23 CP is more than SP, he makes a loss. Loss = CP-SP = 2019.23 - 2000 = 19.23Loss Percent = [(19.23)/(2019.23)]x100 = 0.95 %.
Q: The least number of complete years in which a sum of money put out at 20% C.I. will be more than doubled is ? 1532 05b5cc6e2e4d2b4197774ec25
5b5cc6e2e4d2b4197774ec25- 13 yearsfalse
- 24 yearstrue
- 32.5 yearsfalse
- 42 yearsfalse
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Answer : 2. "4 years"
Explanation :
Answer: B) 4 years Explanation: P1+20100n > 2P Now, (6/5 x 6/5 x 6/5 x 6/5) > 2. So, n = 4 years.