Students please note that the best way to solve this equation is to work backwards. Since Soumya was last to eat the cookies and she ate 3 cookies, the total number of cookies left when she entered the room = (3 × 4) = 12. This should be Soumya’s sharethat was left in the box uneaten. Hence just before Soumya entered, Swetha, Sneha and Swarna would have eaten their share of 12 cookies each.
Total number of cookies left when Senha entered = (12 × 4) = 48.
This in turn should have been the combinedshares of Sneha and Soumya (24 × 2) that was left in the box uneaten. So Just before Sneha entered, Swetha and Swarna should have eaten 24 cookies each. In other words number of cookies left, just before Swarna entered= (24 × 4) = 96 . Now this shouldhave been the combined shares of Swarna, Sneha and Soumya (3 × 32) that was kept in the box by Swetha. So just before Swarna entered, Swetha must have eaten her share of 32 cookies. Hence total number of cookies given by Prem uncle = (32 × 4) = The situationis also shown in the following table:
We can see that Sneha ate 15 cookies in all.