IIT JEE Practice Question and Answer
8Q: 64 boys and 40 girls form a group for social work. During their membership drive, the same number of boys and girls joined the group. How many members does the group have now, if the ratio of boys to girls is 4:3 ? 6101 05b5cc6ebe4d2b4197774ee7d
5b5cc6ebe4d2b4197774ee7d- 1168true
- 2201false
- 3147false
- 4154false
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Answer : 1. "168"
Explanation :
Answer: A) 168 Explanation: Let us say x boys and x girls joined the group. (64 + x)/(40 + x) = 4/3 192 + 3x = 160 + 4x => x = 32 Number of members in the group = 64 + x + 40 + x = 104 + 2x = 168.
Q: The marks obtained by Vijay and Amith are in the ratio 4:5 and those obtained by Amith and Abhishek in the ratio of 3:2. The marks obtained by Vijay and Abhishek are in the ratio of ? 6083 05b5cc6e0e4d2b4197774eb98
5b5cc6e0e4d2b4197774eb98- 14:5false
- 26:5true
- 33:2false
- 41:3false
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Answer : 2. "6:5"
Explanation :
Answer: B) 6:5 Explanation: 4:5 3:2 -------=> 12:15:10 12:10 => 6:5
Q: In a fort, there are 1200 soldiers. If each soldier consumes 3 kg per day, the provisions available in the fort will last for 30 days. If some more soldiers join, the provisions available will last for 25 days given each soldier consumes 2.5 kg per day. Find the number of soldiers joining the fort in that case ? 6063 05b5cc6e5e4d2b4197774ed24
5b5cc6e5e4d2b4197774ed24- 1693false
- 2741false
- 3528true
- 4654false
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Answer : 3. "528"
Explanation :
Answer: C) 528 Explanation: Assume x soldiers join the fort. 1200 soldiers have provision for 1200 (days for which provisions last them)(rate of consumption of each soldier)= (1200)(30)(3) kg. Also provisions available for (1200 + x) soldiers is (1200 + x)(25)(2.5) k As the same provisions are available=> (1200)(30)(3) = (1200 + x)(25)(2.5) x = ([(1200)(30)(3)] / (25)(2.5)) - 1200 => x = 528.
Q: If 78K928L is divisible by 6, then which of the following can Q and R take ? 6055 05b5cc741e4d2b4197774f995
5b5cc741e4d2b4197774f995- 1K=2 & L=3false
- 2K=1 & L=4true
- 3K=1 & L=2false
- 4K=3 & L=3false
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Answer : 2. "K=1 & L=4"
Explanation :
Answer: B) K=1 & L=4 Explanation: As per divisibility rule a number is divisible by 6 means it should be divisible by 2 and 3 case 1 : the divisibility rule for 2 is the number should be end with even number in this case R =2 & R=4 case 2 : The divisibility rule for 3 is the sum of numbers should be divisible by 3so if we take option (2) Q=1 & R=4 the sum is 39 if we take option (3) Q=1 & R=2 the sum is 37 So Option (2) is correct 39 is divided by 3
Q: Taps X and Y can fill a tank in 30 and 40 minutes respectively.Tap Z can empty the filled tank in 60 minutes.If all the three taps are kept open for one minute each,how much time will the taps take to fill the tank? 6034 05b5cc764e4d2b4197774fde1
5b5cc764e4d2b4197774fde1- 148minfalse
- 272minfalse
- 324mintrue
- 4None of thesefalse
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Answer : 3. "24min"
Explanation :
Answer: C) 24min Explanation: Given taps X and Y can fill the tank in 30 and 40 minutes respectively. Therefore, part filled by tap X in 1 minute = 1/30 part filled by tap Y in 1 minute = 1/40 Tap Z can empty the tank in 60 minutes. Therefore, part emptied by tap Z in 1 minute = 1/60 Net part filled by Pipes X,Y,Z together in 1 minute = [1/30 +1/40 - 1/60] = 5/120 = 1/24 i.e., the tank can be filled in 24 minutes.
Q: A boatman can row 3 km against the stream in 20 minutes and return in 18 minutes. Find the rate of current ? 5979 05b5cc6ebe4d2b4197774ee46
5b5cc6ebe4d2b4197774ee46- 11/3 kmphfalse
- 22/3 kmphfalse
- 31/4 kmphfalse
- 41/2 kmphtrue
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Answer : 4. "1/2 kmph"
Explanation :
Answer: D) 1/2 kmph Explanation: Speed in upstream = Distance / Time = 3 x 60/20 = 9 km/hr. Speed in downstream = 3 x 60/18 = 10 km/hr Rate of current = (10-9)/2 = 1/2 km/hr.
Q: 3 men, 4 women and 6 children can complete a work in 7 days. A woman does double the work a man does and a child does half the work a man does. How many women alone can complete this work in 7 days ? 5976 05b5cc6e5e4d2b4197774ecfc
5b5cc6e5e4d2b4197774ecfc- 16false
- 29false
- 35false
- 47true
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Answer : 4. "7"
Explanation :
Answer: D) 7 Explanation: Let 1 woman's 1 day work = x. Then, 1 man's 1 day work = x/2 and 1 child's 1 day work x/4. So, (3x/2 + 4x + + 6x/4) = 1/7 28x/4 = 1/7 => x = 1/49 1 woman alone can complete the work in 49 days. So, to complete the work in 7 days, number of women required = 49/7 = 7.
Q: Without any stoppage, a person travels a certain distance at an average speed of 42 km/h, and with stoppages he covers the same distance at an average speed of 28 km/h. How many minutes per hour does he stop? 5945 05b5cc75ee4d2b4197774fcbb
5b5cc75ee4d2b4197774fcbb- 115 minutesfalse
- 220 minutestrue
- 318 minutesfalse
- 422 minutesfalse
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Answer : 2. "20 minutes"
Explanation :
Answer: B) 20 minutes Explanation: Let the total distance to be covered is 84 kms.Time taken to cover the distance without stoppage = 84/42 hrs = 2 hrsTime taken to cover the distance with stoppage = 84/28 = 3 hrs.Thus, he takes 60 minutes to cover the same distance with stoppage.Therefore, in 1 hour he stops for 20 minutes.