A mixture of milk and water measures 60 gallons. It contains 20% water. How many gallons of water should be added to it so that water may be 25%?
a) 6 gallons
b) 4 gallons
c) 8 gallons
d) 10 gallons
e) 5 gallons
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b
Looks like nobody knows the answer.
By the way what is your answer ?
I find it quite simple..although i dont exactly know that m correct or not!!!
60 x
20 100
\ /
25
/ \
75 5
so,15:1=60:x
so, x=4 gallons.
plz guide if i’m wrong anywhere
B
I am getting 4 Gallons …
Soln :-
initial quantity of water = 20/100(60) = 12 gallons
New quantity of water = (12 +x) gallons
Total quantity of mixture will become = (60+x) gallons
New quantity of water = 25/100(60+x)
==> 25/100(60+x) = 12+x
Solving for x , we get 4 gallons ..
Well done Aliva & Ram !
Till now we solved the question with two approaches. One from Allegation & other from equation.
Can we have third punter approach with mental calculation as well ?
B for me…
20%(60) = 12 gallons of water
(60+x gallons) mixture —-100%
(12+x gallons) water ——-25%
(12+x) 100 = (60+x) 25
x = 4 gallons of water to be added
Option B
Thanx Gmat Team
B. 48/75% – 60
20% of 60 is 12
60-12=48
this 48 is 75%
therefore 100% is 48*(4/3)=64
ans is 64-60=4
B)