IIT JEE Practice Question and Answer
8Q: K is 50% faster than L. If L starts at 9 A.M. and K starts at 10 A.M. L travels at a speed of 50 km/hr. If L and K are 300 kms apart, The time when they meet when they travel in opposite direction is ? 2346 05b5cc741e4d2b4197774f9e5
5b5cc741e4d2b4197774f9e5- 112 pmtrue
- 21 pmfalse
- 311 amfalse
- 411:30 amfalse
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Answer : 1. "12 pm"
Explanation :
Answer: A) 12 pm Explanation: let 't' be the time after which they met since L starts. Given K is 50% faster than L 50 t + 1.5*50(t-1) = 300 50 t +75 t = 300 + 75 t = 375 / 125 = 3 hrs past the time that L starts So they meet at (9 + 3)hrs = 12:00 noon.
Q: The ratio of boys and girls in a school is 9:5.If the total number of students in the school is 1050.Then number of boys is 2344 05b5cc6b8e4d2b4197774d642
5b5cc6b8e4d2b4197774d642- Show AnswerHide Answer
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Answer :
Explanation :
Let the ratio be 'R' Total number of students = 1050 Then, 9R + 5R = 1050 14R = 1050 => R = 75 Hence, the number of boys = 9R = 9 x 75 = 675
Q: A can build a wall in 16 days while B can destroy it in 8 days. A worked for 5 days. Then B joined with A for the next 2 days. Find in how many days could A build the remaining wall ? 2343 05b5cc6cee4d2b4197774e208
5b5cc6cee4d2b4197774e208- 112 daysfalse
- 214 daysfalse
- 313 daystrue
- 416 daysfalse
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Answer : 3. "13 days"
Explanation :
Answer: C) 13 days Explanation: Now, Total work = LCM(16, 8) = 48 A's one day work = + 48/16 = + 3 B's one day work = - 48/8 = -6 Given A worked for 5 days to build the wall => 5 days work = 5 x 3 = + 15 2days B joined with A in working = 2(3 - 6) = - 6 Remaining Work of building wall = 48 - (15 - 6) = 39 Now this remaining work will be done by A in = 39/3 = 13 days.
Q: The law of increasing opportunity costs states that 2343 05b5cc642e4d2b4197774bb24
5b5cc642e4d2b4197774bb24- 1along a production possibilites curve, increases in the production of one good make the production of that good easier and easierfalse
- 2increases in wages cause increases in the costs of productionfalse
- 3costs of production increases and then decreasesfalse
- 4along a production possibilities curve, increases in the production of one good require larger and larger sacrifices of the other goodtrue
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Answer : 4. "along a production possibilities curve, increases in the production of one good require larger and larger sacrifices of the other good"
Explanation :
Answer: D) along a production possibilities curve, increases in the production of one good require larger and larger sacrifices of the other good Explanation: Opportunity cost is the cost of what you are giving up to do what you are currently doing. If you can either go to work or go to the beach, and you choose to work, the opportunity cost of working is the value you would have gotten had you gone to the beach. The law of increasing opportunity costs states that as you increase production of one good, the opportunity cost to produce an additional good will increase.
Q: What comes next in this sequence 196, 169, 144, 121, 100, 81, ? 2343 05b5cc6ade4d2b4197774d13e
5b5cc6ade4d2b4197774d13e- 177false
- 274false
- 367false
- 464true
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Answer : 4. "64"
Explanation :
Answer: D) 64 Explanation: The given number series follows a pattern that 196, 169, 144, 121, 100, 81, ? -27 -25 -23 -21 -19 -17 => 81 - 17 = 64 Therefore, the series is 196, 169, 144, 121, 100, 81, 64.
Q: 88 cubic centimetres of silver is drawn into a wire 1 mm in diameter. The length of the wire in metres will be ? 2343 05b5cc723e4d2b4197774f659
5b5cc723e4d2b4197774f659- 1112 mtsfalse
- 284 mtstrue
- 396 mtsfalse
- 4108 mtsfalse
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Answer : 2. "84 mts"
Explanation :
Answer: B) 84 mts Explanation: Vol of silver = πR2h = 66 C.C Given D= 1mm => R = D/2 = 1/20 cm => 227×1202×h = 66 = 66 x 400 x (7/22) = 8400 cm = 84 mtrs.
Q: A man can row 6 kmph in still water. When the river is running at 1.2 kmph, it takes him 1 hour to row to a place and back. What is the total distance traveled by the man ? 2343 05b5cc6d7e4d2b4197774e728
5b5cc6d7e4d2b4197774e728- 14.58 kmsfalse
- 26.35 kmsfalse
- 35.76 kmstrue
- 45.24 kmsfalse
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Answer : 3. "5.76 kms"
Explanation :
Answer: C) 5.76 kms Explanation: Speed in still water = 6 kmph Stream speed = 1.2 kmph Down stream = 7.2 kmph Up Stream = 4.8 kmph x/7.2 + x/4.8 = 1 x = 2.88 Total Distance = 2.88 x 2 = 5.76 kms
Q: Find the next number in the following number series? 11, 13, 30, 96, ? 2341 05b5cc688e4d2b4197774c318
5b5cc688e4d2b4197774c318- 1264false
- 2392true
- 3412false
- 4459false
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Answer : 2. "392"
Explanation :
Answer: B) 392 Explanation: The given number series 11, 13, 30, 96, ? follows a pattern that, 11 11 x 1 + 2 = 13 13 x 2 + 4 = 30 30 x 3 + 6 = 96 96 x 4 + 8 = 392 Hence, the next number in the given series is 392.