In a mixture of milk and water, the proportion of water by weight was 75\%. If in the 60 gms mixture 15 gm of water was added, what would be the percentage of water?
(a)75\%
(b)88\%
(c)90\%
(d)100\%
(e)None of these
Answer
Answer (as printed): E
Explanation
Weight of water in 60 gms mixture = 75\% of 60 gm $$=\left(\frac{75}{100} \times 60\right) \mathrm{gm}=45 \mathrm{gm} .$$ Weight of water in 75 gms mixture $=(45+15) \mathrm{gm}=60 \mathrm{gm}$. $$\text { ∴ } \text { Required percentage }=\left(\frac{60}{75} \times 100\right) \%=80 \% .$$
Explanation as extracted from the printed page; notation may be imperfect.