Hi,

We are asked to get the maximum number of things within a fixed amount of money. To get the maximum number of products, we have to maximize the number of products of lowest price.

For 1:

cheaper price is 2$ and we have to buy the products exactly with 25$.

25/2=12.5 , If we buy 12 pair brandX socks, 12*2=24, wehave 1$ left. But that cant be happened!!

If we buy 11 pair brandX socks11*2=22, we have left 3$ buy which we can buy a pair of brand y socks. So total 11+1 =12 pair

Answer:12(D)

For 2:

similar to the 1st one:

65/3=21+something...., so 21*3=63, 2$ left; so it is not acceptable!!

next,20*3=60, 5$ left, we can not buy Product B with 5 $ ;so it is not acceptable

19*3=57$, 8$ left by which we can buy 2 package of B, so total 19+2=21(E)