Correct Answer For Question 7

by Anjali
(Delhi)

According to question :

G = 19W
Cu = 9W

Now let required ratio of gold and copper(G and Cu) be

G/Cu = x

So, xCu + Cu/W = 15

Cu(1+x) = 15W

9W(1+x) = 15w

1+x = 15/9

x = 15/9 - 1 = 6/9 = 2/3

So answer is not 3/2 but 2/3.