IIT JEE Practice Question and Answer
8Q: Lucky started working 2 years ago. Her starting salary was half of Karthik's salary at that time. Each year since then Lucky and Karthik have received a rise of 10% in their respective salary. What percentage (to the nearest percent) of Karthik's current salary is Lucky's current salary ? 1618 05b5cc6cfe4d2b4197774e2f9
5b5cc6cfe4d2b4197774e2f9- 175%false
- 222.5%false
- 335%false
- 450%true
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Answer : 4. "50%"
Explanation :
Answer: D) 50% Explanation: Let the salary of Karthik 2 years ago be Rs.100So, Lucky's salary 2 years ago was Rs.50 Karthik's present salary has seen two 10 percent increases. So as Lucky's salary. So, Karthik's salary 1 year ago = 100 + 10% of 100 = 100 + 10 = 110.Karthik's present salary = 110 + 10% of 110 = 110 + 11 = 121. Lucky's salary 1 year ago = 50 + 10% of 50 = 50 + 5 = 55Lucky's present salary = 55 + 10% of 55 = 55 + 5.5 = 60.5 Lucky's present salary of 60.5 = 50% of Karthik's present salary of 121.
Q: Which method of expressing direction is indicated in the illustration? 1617 05b5cc633e4d2b4197774b9dc
5b5cc633e4d2b4197774b9dc- 1Sectionfalse
- 2Interjuctionfalse
- 3Intersectiontrue
- 4None of the abovefalse
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Answer : 3. "Intersection"
Explanation :
Answer: C) Intersection Explanation:
Q: A fair coin is tossed 11 times. What is the probability that only the first two tosses will yield heads ? 1617 05b5cc6c8e4d2b4197774df23
5b5cc6c8e4d2b4197774df23- 1(1/2)^11true
- 2(9)(1/2)false
- 3(11C2)(1/2)^9false
- 4(1/2)false
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Answer : 1. "(1/2)^11"
Explanation :
Answer: A) (1/2)^11 Explanation: Probability of occurrence of an event, P(E) = Number of favorable outcomes/Numeber of possible outcomes = n(E)/n(S) ⇒ Probability of getting head in one coin = ½, ⇒ Probability of not getting head in one coin = 1- ½ = ½, Hence, All the 11 tosses are independent of each other. ∴ Required probability of getting only 2 times heads =122×129=1211
Q: Food : Stomach : : Fuel : ? 1617 05b5cc73de4d2b4197774f977
5b5cc73de4d2b4197774f977- 1truckfalse
- 2Planefalse
- 3Enginetrue
- 4Automobilefalse
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Answer : 3. "Engine"
Explanation :
Answer: C) Engine Explanation: Food is processed by the stomach to provide energy for the functioning of the body.Similarly, fuel is processed by the engine to provide energy for the functioning of automobile.
Q: If 25% of a number is subtracted from a second number, the second number reduces to its four-sixth. What is the ratio of the first number to the second number ? 1617 05b5cc6dee4d2b4197774ea46
5b5cc6dee4d2b4197774ea46- 14:3true
- 22:3false
- 33:2false
- 45:3false
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Answer : 1. "4:3"
Explanation :
Answer: A) 4:3 Explanation: Let the numbers be p & q q-p/4 = 4q/6 => q-4q/6 = p/4 => 2q/6 = p/4 => p/q = 4/3
Q: Which of the following chemical compounds has the highest boiling point? 1617 05b5cc6b5e4d2b4197774d52a
5b5cc6b5e4d2b4197774d52a- 1Dimethyl ether (CH3OCH3)false
- 2Methanol (CH3OH)true
- 3Methane (CH4)false
- 4Nonefalse
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Answer : 2. "Methanol (CH3OH)"
Explanation :
Answer: B) Methanol (CH3OH) Explanation: Chemical Compounds with stronger intermolecular forces have higher boiling points. The order of strengths of intermolecular forces is: London dispersion < dipole-dipole < H-bonding Methane (CH4) — London dispersion forces Dimethyl ether (CH3OCH3) — dipole-dipole attractions Methanol (CH3OH) — hydrogen bonding Therefore, Methanol - CH3OH with H-Bonding have highest Boiling Point among the given chemical compounds.
Q: Two pipes A and B can separately fill a cistern in 60 min and 75 min respectively. There is a third pipe in the bottom of the cistern to empty it. If all the three pipes are simultaneously opened, then the cistern is full in 50 min. In how much time, the third pipe alone can empty the cistern ? 1617 05b5cc6e7e4d2b4197774edb5
5b5cc6e7e4d2b4197774edb5- 185 minfalse
- 295 minfalse
- 3105 minfalse
- 4100 mintrue
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Answer : 4. "100 min"
Explanation :
Answer: D) 100 min Explanation: Work done by the third pipe in 1 min = 1/50 - (1/60 + 1/75) = - 1/100.[-ve sign means emptying] The third pipe alone can empty the cistern in 100 min.
Q: In a joint family, there are 24 members whose age is decreased by 4 months, when one girl aged 24 years is replaced by a new boy. Find the age of the new boy ? 1616 05b5cc6c5e4d2b4197774dd73
5b5cc6c5e4d2b4197774dd73- 118 yearsfalse
- 212 yearsfalse
- 315 yearsfalse
- 416 yearstrue
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Answer : 4. "16 years"
Explanation :
Answer: D) 16 years Explanation: Age of new boy = (Age of moved girl) – (Number of family members × Decreased in average) = 24 – 24×4/12 = 24 – 8 = 16 years.