1) 6 children can do a piece of work in 12 days while 8 men can do the same work in 18 days. The same work can be done by 18 women in 10 days. 4 children, 12 men and 20 women work together for 2 days. If only children have to complete remaining work in 1 day, then find the required number of children?
a)24
b)36
c)30
d)35
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Answer b)36
let us assume that the amount of work be 1440 units
6 children in 12 days can do – 1440 units. So – 1 children‘s rate of doing work = 20 units/day.
18 women in 10 days can do – 1440 units. So – 1 women‘s rate of doing work = 8 units/day.
8 men in 18 days can do – 1440 units. So – 1 man‘s rate of doin work = 10 units/day.
4 children can do – 4*20 = 80 units/day.
12 men can do – 12*10 = 120 units/day.
20 women can do – 20*8 = 160 units/day
Together 4 children, 12 men & 20 women can do = 360 units/day.
In 2 days they will do = 2*360 = 720 units.
Amount of work left = 1440 – 720 = 720 units.
So if only children are given to complete the left task of 720 units in one day, then Required number of children will be = 720/20 = 36 is the answer.
2) Two pipes P & Q can fill up half full tank in 1.2 hours. The tank was initially empty. Pipe Q was kept open for half the time required by pipe P to fill the tank by itself. Then, Pipe Q was kept open for as much time as was required by pipe Q to fill up 1/3rd of the tank by itself. It was then found that the tank was 5/6th full. The least time in which any of the pipes can fill up the tank fully is.
a)6hrs
b)4:30hrs
c)5hrs
d)4hrs
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Answer d)4hrs
P + Q = 50%/1.2 = 41.66%
(where P & Q represent the work per hour of pies P & Q respectively).
Solve using options to see which one fits the remaining conditions of the problem.
For eg, if we check option b(4 hrs), then we get that the work of the faster pipe(say P) = 25 %
Then Q = 16/66%
Then Q was open for 4/2= 2 hours and P was open 6/3= 2 hours.
Work done = 25% * 2 + 16.66% * 2 = 83.33% = 5/6 of work hence this option is correct.
3) A tank holds 100 litres of water. Its inlets is 7 cm in diameter and fills the tank at 5 litres/min. The outlet of the tank is twice the diameter of the inlet. How many minutes will it take to empty the tank if the inlet is shut off, when the tank is full and the outlet is opened?
a)5min
b)8min
c)10min
d)9min
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Answer c) 10min
Since rate of filling capacity is directly proportional to the diameter of the inlet/outlets
So 5/x = 7p/14p we get x = 10 litres /min so time taken to empty the tank becomes 100/10 = 10.0 mins.
4) Three carpenters have to make 80 chairs. They are known to make 20 pieces evrey minute working together. The first carpenter began working alone and made 20 pieces of chairs having worked for sometime more than three minutes. The remaining part of the work was done by the second and the third cook working together. It took a total of 8 minutes to make 80 chairs. How many minutes would it take the first cook alone to cook 160 chairs for a function the next day?
a)35mins
b)30mins
c)32mins
d)25mins
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Answer c)32mins
From the condition of the problem and a little bit of trial and error we can see that the first carpenter
worked for for 4 mins and 2nd and 3rd carpenter also worked for 4 mins. As 4A + 4(B+C) = 49A + B + C)
and we know that A + B + C = 20 pieces per minute.
So , the first carpenter make 20 pieces in 4 mins. To make 160 pieces of chairs he would take 32 mins.
5)There are two taps A & B connected to a tank. Capacity of the tank is 40 L. Tap A can fill the tank in 10 hour. Tap B can empty the tank in 20 hour. How much time will both the taps take to fill the tank when both are open simulataneously? It is given that water evaporates at the rate of 2.5% of the total capacity of tank in an hour
a)30hr.
b)35hr.
c)40hr.
d)38hr.
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Answer c)40hr.
since the capacity of tank is 40 L.
Tap A takes 10 hr which means its rate of filling is = 4 L/hr.
Similarly B empties the tank in 20 hr so its rate of emptying the tank is = 2 L/hr
And given 2.5 % of total tank capacity get evaporated in every 1 hour which is = 1L/hr
So, net rate of filling is 4 – 2 – 1 = 1 L/hr
Hence, when both taps are open it will take 40/1 = 40 hr.
6)5, 10, 8, 12, 11, 14, ?, 16
a) 17
b) 13
c) 20
d) 14
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Answer d)14
two alternate series
5,8 , 11, ?
+3 , +3 ,+3
7)4, ?, 144, 400, 900, 1764
a) 25
b) 36
c) 49
d) 100
e) 120
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Answer b) 36
difference of 2^2 , 6^2, 12^2, 20^2 , 30^2, 42^2
8)51975, 9450, 2100, 600, 240, 160, ?
a) 80
b) 120
c) 320
d) 240
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Answer c) 320
*2/11, *2/9 , 2/7, 2/5 , 2/3 , *2/1
9)20, 20, 10, 30, 7.5, ?
a) 32.5
b) 37.5
c) 41.25
d) 43.25
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Answer b)37.5
20*1 = 20
20 ÷ 2 = 10
10 * 3 = 30
30 ÷4 = 7.5
7.5 * 5 = 37.5
10)198, 194, 185, 169, ?
a) 92
b) 136
c) 144
d) 112
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Answer c) 144
difference of -2^2, -3^2 , -4^2, -5^2
Also check out Quantitative Aptitude Quiz for IBPS | SBI | RBI – Set 240
