14 pumps of equal capacity can fill a tank in 6 days. If the tank has

Question

14 pumps of equal capacity can fill a tank in 6 days. If the tank has to be filled in 4 days, the number of extra pumps needed is :

A. 7
B. 14 
C. 21 
D. 28
E. 29

SaurbahThakur · Answer

This is a problem related to inverse variation since a decrease in the number of days means increase in the Number of pumps.

In 6 days Number of pump can fill a tank = 14
In 1 day Number of pump can fill a tank = 14 × 6 = 84
In 4 days Number of pump can fill a tank = 84/4= 21

the number of extra pumps needed = 21 - 14 = 7 pumps .

Hence, the number of extra pumps needed is 7.

HOPE THIS WILL HELP YOU..

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GMATinsight · Answer

CONCEPT :  \frac{(Machine_Power * Time)}{Work} = Constant

i.e.  \frac{(M_1 * T_1)}{W_1} = \frac{(M_2 * T_2)}{W_2}

i.e.  \frac{(14 * 6)}{1} = \frac{(M_2 * 4)}{1}

i.e.  M_2 = 21

Additional Pumps needed  = 21 - 14 = 7

Answer: Option A

Satishqwerty · Answer

The work done will be constant

14 pumps in 6 days will fill  14 	imes 6 = 84  litres.

Now we have only 4 days so need pumps =  \frac{84}{4} = 21  pumps.

Read the question carefully, we need to answer extra pumps needed.

Extra pumps =  21 - 14 = 7

OA, A

dimri10 · Answer

ratio of 14 to 6

now: to get the capacity in 1 day you divide 6 by 6 and multiply the pums in 6, so
84 pumps will do the work in 1 day
the same logic
if 84 pums can do the work in 1 day than 21 can do the work in 4 days (multiplyqdivide same ratio)
21-14 is 7

yashikaaggarwal · Answer

6 pumps are filling tank in 14 days.
Take LCM of 6&14 for knowing capacity.
LCM of 6&14 = 42
So,
6 pumps can fill 42 litre in 14 days.
6Pumps = 42 litres
1 Pump = 7 litres
7litres in 14 days
0.5litre = 1day

Therefore a pump can fill 0.5litre per day.
We have to fill tank in 4 days.
1 pump can 4*0.5litre = 2litres in 4 days
42/2 = 21 pumps can fill 42 litres in four days.

We already have 14 pumps with us
Required - Existing = Additional units
21-14 = 7 is the additional units we need.

Answer is A

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Babineaux · Answer

If 14 equal capacity pump fill a tank in 6 days,

Now to fill the tank in 4 days 14x6/4 number of equal capacity pumps are required.

Equals to 21.

Now extra 21-14 = 7 number of extra pumps are required.

IMO ans is A.

bM22 · Answer

Given: 14 pumps of equal capacity can fill a tank in 6 days.
=> 6 days needed by 14 pumps to fill the tank.
=> If the tank is to be filled in 1 day, 14*6 pumps would be needed. (also the total capacity of tank)
=> If the tank is to be filled in 4 days, 21 pumps would be needed.

Extra pumps required: 7.

Answer A.

satya2029 · Answer

X*R*T=1
14*R*6=1
R=1/84
X*R*4=1
X=1/(4*R)
X=21
Extra=21-14=7
A:)

inesricardette · Answer

Here is my approach:

You know that you can fill the tank in 6 days with 14 pumps
If you double the number of pumps you will divide the time by 2
14 pumps = 6 days
28 pumps = 3 days
Since you need to find the number of pumps to add for 4 days, it needs to be less than 14 and the only answer is 7.

Hope this helps.

bumpbot · Answer

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14 pumps of equal capacity can fill a tank in 6 days. If the tank has

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