IIT JEE Practice Question and Answer
8Q: Four person A, B, C and D. The sum of their present age is 176. Four years ago ratio of their age was 11: 9 : 6 : 14, then find who is eldest and youngest among them ? 1901 05b5cc6c1e4d2b4197774db82
5b5cc6c1e4d2b4197774db82- 1A is eldest & C is youngestfalse
- 2D is eldest & C is youngesttrue
- 3C is eldest & A is youngestfalse
- 4A is eldest & B is youngestfalse
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Answer : 2. "D is eldest & C is youngest"
Explanation :
Answer: B) D is eldest & C is youngest Explanation: Given sum of present ages of A, B, C & D A + B + C + D = 176 and also given that, (A-4) : (B-4) : (C-4) : (D-4) = 11 : 9 : 6 : 14 Let the ratio = x => A-4 + B-4 + C-4 + D-4 = 11x + 9x + 6x + 14x => (A + B + C + D ) - 16 = 40x => 176 - 16 = 40x => x = 4 => A = 44 + 4 = 48 => B = 40 => C = 28 => D = 60 Therefore, from the above conclusions D is eldest with 60 years and C is youngest with 28 years of ages.
Q: Who proved that microorganisms cause disease? 1901 05b5cc69be4d2b4197774c7cd
5b5cc69be4d2b4197774c7cd- 1van Leeuwenhoekfalse
- 2Kochtrue
- 3Flemingfalse
- 4Pasteurfalse
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Answer : 2. "Koch"
Explanation :
Answer: B) Koch Explanation:
Q: Thrice the square of a natural number decreased by 4 times the number is equal to 50 more than the number. The number is ? 1900 05b5cc6dfe4d2b4197774eabc
5b5cc6dfe4d2b4197774eabc- 15true
- 24false
- 37false
- 46false
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Answer : 1. "5"
Explanation :
Answer: A) 5 Explanation: Let the number be x. Then, 3x2 - 4x = x + 50 3x2- 5x - 50 = 0 (3x + 10)(x - 5) = 0 x = 5
Q: Which continent has the most countries? 1900 05b5cc655e4d2b4197774bd54
5b5cc655e4d2b4197774bd54- 1Asiafalse
- 2Africatrue
- 3Antarcticafalse
- 4Europefalse
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Answer : 2. "Africa"
Explanation :
Answer: B) Africa Explanation: We know that, there are 7 continents in the world. They are : Asia, Africa, Australia, North America, South America, Europe and Antarctica. Africa - 53 countries Asia - 48 countries Europe - 45 countries Antarctica - 0 countries Hence, the continent Africa has most number of countries with 53 countries and in second place Asia has 48 , third Europe has 45 countries.
Q: CTRL + ] is used for 1899 05b5cc6a0e4d2b4197774ca3d
5b5cc6a0e4d2b4197774ca3d- 1Re-dofalse
- 2Right align textfalse
- 3Increase in font sizetrue
- 4Expand or collapse the ribbonfalse
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Answer : 3. "Increase in font size"
Explanation :
Answer: C) Increase in font size Explanation: CTRL + ] is a computer shortcut and is used for Increase in font size. Shortcuts : Re-do ---- Ctrl + Y Right align text ---- Ctrl + R Expand or collapse the ribbon ---- Ctrl + F1
Q: Two trains are moving in opposite directions at 60 km/hr and 90 km/hr. Their lengths are 1.10 km and 0.9 km respectively. The time taken by the slower train to cross the faster train in seconds is ? 1899 05b5cc6d7e4d2b4197774e6e2
5b5cc6d7e4d2b4197774e6e2- 142 secfalse
- 244 secfalse
- 346 secfalse
- 448 sectrue
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Answer : 4. "48 sec"
Explanation :
Answer: D) 48 sec Explanation: Relative speed = 60 + 90 = 150 km/hr. = 150 x 5/18 = 125/3 m/sec. Distance covered = 1.10 + 0.9 = 2 km = 2000 m. Required time = 2000 x 3/125 = 48 sec.
Q: Find the next number in the following number series? 410, 409, 413, 404, ? 1898 05b5cc662e4d2b4197774bea6
5b5cc662e4d2b4197774bea6- 1412false
- 2415false
- 3418false
- 4420true
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Answer : 4. "420"
Explanation :
Answer: D) 420 Explanation: The given number series 410, 409, 413, 404, ? , follows a pattern that 410 410 - 13 = 409409 + 22 = 413413 - 33 = 404404 + 42 = 420 Hence, the next number in the given series is 420.
Q: A jogger running at 9 km/hr along side a railway track is 260 m ahead of the engine of a 140 m long train running at 45 km/hr in the same direction. In how much time will the train pass the jogger ? 1898 05b5cc6e5e4d2b4197774ed29
5b5cc6e5e4d2b4197774ed29- 125 secfalse
- 240 sectrue
- 338 secfalse
- 432 secfalse
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Answer : 2. "40 sec"
Explanation :
Answer: B) 40 sec Explanation: Speed of train relative to jogger = 45 - 9 = 36 km/hr.= 36 x 5/18 = 10 m/sec. Distance to be covered = 260 + 140 = 400 m. Time taken = 400/10 = 40 sec.

