A vessel contains 175 liters of a mixture of oil and water in the ratio of 4:3. If n liters of oil and (n-25) liters of water is added to the mixture, then the ratio of oil to water becomes 7:5. Find the value of n?
a) 75
b) 35
c) 125
d) 90
e) None of these
Sol:
The quantity of oil in the vessel = 175 * 4/(4 + 3)
= 175 * 4/7 = 100 liters
The quantity of water in the vessel = 175 – 100 =
75 liters
(100 + n)/(75 + n – 25)) = 7/5
500 + 5n = (50 + n) * 7
500 + 5n = 350 + 7n
2n = 150
n = 75
