IIT JEE Practice Question and Answer
8Q: Virus doubles every 3 mins. It is 'K' in 1 hour, when was it K/4 ? 1497 05b5cc711e4d2b4197774f3a3
5b5cc711e4d2b4197774f3a3- 129 minfalse
- 225 minfalse
- 354 mintrue
- 457 minfalse
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Answer : 3. "54 min"
Explanation :
Answer: C) 54 min Explanation: If virus is K in 1hr i.e 60 minthen in 57 min it was K/2 as it doubles every 3 minutes=> In 54 min it was K/4.At 54 minutes it was K/4.
Q: In a class, seven students are standing in a row. Q is standing left to R but right to P. O is standing right to N and left to P. Similarly, S is standing right to R and left to T. Find out who is standing in the middle ? 1723 05b5cc711e4d2b4197774f394
5b5cc711e4d2b4197774f394- 1Qtrue
- 2Rfalse
- 3Pfalse
- 4Sfalse
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Answer : 1. "Q"
Explanation :
Answer: A) Q Explanation: As from the given conditions;Order is N O P Q R S THere the student standing in the middle is 'Q'.
Q: What is better, to have 70% discount or 40 and 30% discount consequently ? 2380 05b5cc70ee4d2b4197774f38f
5b5cc70ee4d2b4197774f38f- 140% is betterfalse
- 270% is bettertrue
- 3Both are samefalse
- 4Nonefalse
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Answer : 2. "70% is better"
Explanation :
Answer: B) 70% is better Explanation: Let Price be Rs.100 1st CASE: Then 100 x 70/100 = 70=> price after discount = 100-70 = Rs.30 2nd CASE: Then 100 x 40/100 = 40=> price after discount = 100-40 = Rs.60then60 x 30/100 = 18=> price after 2 consequent discount = 60-18 = Rs.42 =>from 1 and 2 cases, 70% discount is better.
Q: In a row, Kumar is at 7th place from the left and Pawan is at 9th place from the right. When they interchange the positions Kumar becomes 11th from left. How many were seated in the row ? 3197 05b5cc70ee4d2b4197774f385
5b5cc70ee4d2b4197774f385- 119true
- 220false
- 321false
- 427false
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Answer : 1. "19"
Explanation :
Answer: A) 19 Explanation: Initialy from left 7th = kumarfrom right 9th = pawanInterchange kumar = 11th from left, from right kumar = 9th;11+8 = 19;8 is 1,2,3,4,5,6,7(pawan),8,9,10,11(kumar),12,13,14,15,16,17,18,19;simply count the 9th place from right we will get total as 19.
Q: Five farmers have 7,9,11,13 & 14 apple trees respectively in their orchards. Last year each of them discovered that every tree in their own orchard yields exactly the same number of apples. Further, if the 3rd farmer gives one apple to the 1st and the 5th gives 3 to each of the 2nd & d 4th, they would all exactly have the same number of apples, what were the yields per tree in the orchards of the 3rd & 4th farmers ? 12309 05b5cc70ee4d2b4197774f38a
5b5cc70ee4d2b4197774f38a- 117 & 9false
- 29 & 11false
- 39 & 9false
- 411 & 9true
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Answer : 4. "11 & 9"
Explanation :
Answer: D) 11 & 9 Explanation: Let the number of apples in each tree of the 5 farmers be a, b, c, d,e respectively. Therefore total no of apples are 7a, 9b, 11c, 13d and 14e respectively. Given, 7a+1 = 9b+3 = 11c-1 = 13d+3 = 14e-6 = x 9b+3 = 13d+3===> 9b = 13dso take b = 13 and d = 9 9b+3 = 9*13+3 = 120 ie, x=120 substituting7a+1 = 1207a = 119a = 17 11c-1 = 12011c = 121c=11 14e-6 = 12014e = 126e = 9 Yields per tree in the orchards of d 3rd & 4th farmers= 11,9
Q: Which alphabet replaces the question mark ? 63 O 4972 T 3796 L 1514 ? 58 3591 05b5cc70ee4d2b4197774f380
5b5cc70ee4d2b4197774f380- 1Afalse
- 2Bfalse
- 3Ctrue
- 4Dfalse
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Answer : 3. "C"
Explanation :
Answer: C) C Explanation: 6-3 = 3 9-4 = 5 (3x5=15) 15=O7-2 = 5 7-3 = 4 (5x4=20) 20=T9-6 = 3 5-1 = 4 (3x4=12) 12=L Similarly, 4-1 = 3 8-5 = 1 (3x1=3) 3=C
Q: If Reena’s age was twice of her present age, when subtracted from four times three years from hence, with three times the three years before her present age. What will be her age after one year ? 1593 05b5cc70ee4d2b4197774f37b
5b5cc70ee4d2b4197774f37b- 122 yrstrue
- 221 yrsfalse
- 320 yrsfalse
- 424 yrsfalse
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Answer : 1. "22 yrs"
Explanation :
Answer: A) 22 yrs Explanation: Let Reena’s present age be 'K' yrs.Given:{(K+3) x 4} - {(K-3) x 3)} => K = 21 yrsSo her present age is 21 yrs.Then, her age after 1 year is 22 yrs.
Q: Four persons can cross a bridge in 3,7,13,17 minutes.Only two can cross at a time.Find the minimum time taken by the four to cross the bridge ? 4571 05b5cc70ee4d2b4197774f36f
5b5cc70ee4d2b4197774f36f- 117 minutesfalse
- 220 minutestrue
- 334 minutesfalse
- 412 minutesfalse
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Answer : 2. "20 minutes"
Explanation :
Answer: B) 20 minutes Explanation: First send 17 and 7. After 7 minutes, 7 is at finish and 17 needs 10 more minutes to complete his travel. now send 13. After 10 minutes 17 reaches finish and 13 needs 3 more minutes to complete. now send 3. both 3 and 13 reach destination at the same time after 3 minutes. hence the time taken is 7+10+3=20 minutes.