41. The H.C.F of two numbers is 11 and their L.C.M is 7700. If one of the numbers is 275, then the other is:
Answer: 308
Explanation:Here is no explanation for this answer
Workspace
Infosys Global Edge
42. In a class, there are 15 boys and 10 girls. Three students are selected at random. The probability that 1 girl and 2 boys are selected, is:
Answer: 21/46
Explanation:Let's assume the sample space = S
and Event of selecting 1 girl and 2 boys = E
So, n(S) = Number ways of selecting 3 students out of 25 = 25C3
=> (25 * 24 * 23)/(3 * 2 * 1) = 2300.
n(E) = (10C1 * 15C2)
= 10 * [(15 * 14)/(2 * 1)] = 1050.
P(E) = n(E)/n(S) = 1050/2300 = 21/46.
Workspace
IBM Global Edge
43. From its total income, A sales company spent Rs.20,000 for advertising, half of the remainder on commissions and had Rs.6000 left. What was its total income?
Answer: 32000
Explanation:Let total income is X
X=20,000+(X-20,000/2)+6000
X-X/2=20,000-10,000+6000
X/2=16,000
X=32,000
Workspace
Capgemini Global Edge
44. A man can row his boat with the stream at 6 km/h and against the stream in 4 km/h. The man's rate is?
Answer: 1 kmph
Explanation:Man's row in downstream by speed = 6 kmph
and upstream by speed = 4 kmph
so man rate = (6 - 4)/2 = 1 kmph
Workspace
Global Edge
45. A man swims downstream 72 km and upstream 45 km taking 9 hours each time. what is the speed of the current?
Answer: 1.5 kmph
Explanation:Man's downstream speed = 72/ 9 kmph => 8kmph
Man's up stream speed = 45/ 9 => 5 kmph
So speed of current = (8 - 5)/2 = 1.5 kmph
Workspace
Global Edge
46. Three pipes A, B and C can fill a tank in 6 hours. After working at it together for 2 hours, C is closed and A and B can fill the remaining part in 7 hours. The number of hours taken by C alone to fill the tank is:
Answer: 14 hrs
Explanation:Tank part filled by pipes (A+B+C) in 1 hrs = 1/6 ------- (1)
so tank part filled by (A+B+C) in 2 hrs = 2*1/6 = 1/3
Now find the remaining part = (1-1/3) = 2/3
=> (A+B) 7 hs work = 2/3
so (A+B) 1 hrs work = 2/21 ------ (2)
To find the C 1 hrs work use eq. 1 & 2
=> 1/6-2/21 = 1/14
so C alone can fill the tank in 14 hrs.
Workspace
Global Edge
47. Pipe A can fill a cistern in 6 hours less than Pipe B. Both the pipes together can fill the cistern in 4 hours. How much time would A take to fill the cistern all by itself?
Answer: 6 hours
Explanation:Let's assume time required by Pipe A to fill the cistern = X hours
So Time required by Pipe B to fill the cistern = (X + 6) hours
? Both Pipes (A+B) can fill cistern in 1 hour = [1/X + 1/(X + 6)]
Given Both pipe fill the cistern in 4 hours
=> [1/X + 1/(X + 6)] = 1/4 => [(X+6) + X]/(X+6)*x = 1/4
4X + 24 + 4X = X2 + 6x
X2 - 2X - 24 = 0
(X-6)(X+4) = 0
=> A can fill cistern in 6 hours.
Workspace
Global Edge
48. A cistern can be filled by a tap in 4 hours while it can be emptied by another tap in 9 hours. If both taps are opened simultaneously, then after how much time will the cistern get filled ?
Answer: 7.2 hours
Explanation:Time taken by tap A to fill the cistern=4 hrs
so work done by tap A in 1 hour = 1/4th
Time taken by tap B to empty the full cistern = 9 hours
so work done by tap B in 1 hour = 1/9th
=> Work done by (A + B) in 1 hour=(1/4 - 1/9)=5/36
Therefore, the tank will fill the cistern = 36/5 hours=7.2 hours.
Workspace
Wipro Global Edge
49. Two stations A and B are 110 km apart on a straight line. One train starts from A at 7 a.m. and travels towards B at 20 kmph. Another train starts from B at 8 a.m. and travels towards A at a speed of 25 kmph. At what time will they meet?
Answer: 10 a.m.
Explanation:Let they meet x hours after 7 a.m.
Distance covered by A in x hours = 20x km.
Distance covered by B in (x - 1) hours = 25(x - 1) km.
So Total Distance
=> 20x + 25(x - 1) = 110
=> 45x - 25 = 110 => 45x = 135
=> x = 3.
As They meet x hrs after 7 a.m. so they meet at 10 a.m.
Workspace
Global Edge
50. A 600m long train is running at 73 Kmph. How much time Train will take to cross an electric pole?
Answer: 29.58 sec
Explanation:Formula Used: Time = ( Distance / Speed)
As all the option given in sec., so convert the train speed (Kmph) in to mps multiply by 5/18
speed (mps) = 73 * 5/18
Time = 600 / (73 * 5/18)
= (600 * 18 )/(73 * 5) sec
= (10800 / 365)
Time take by Train = 29.58Sec
Workspace
Global Edge
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