Aman bought 42 stamps, some 13¢ and some 18¢. how many of each kind did he buy if the cost was $6.66? if x represents the number of 13 cent stamps and y the 18 cent stamps, which system represents the problem? x + y = 42 and 0.13x + 0.18y = 6.66 x + y = 6.66 and 0.13x = 0.18y 0.13x + 0.18y = 42 and x + y = 6.66

He bought 18 and 24 stamps of 13 cent and 18 cent respectively and equations 0.13x + 0.18y = 6.66, x+y=42 represent the problem.

Explanation:

Since according to the question man bought total 42 stamps in which some are of 13 cent while some are of 12 cent. And, x represents the number of 13 cent and y represents the number of 18 cent.

So, we can write, x+y=42   (1)

Again, according to the question 13x cent+18y cent= 6.66 $ (2)

Since, 1$= 100 Cent, so we can write 13x cent=0.13x $, and 18y cent= 0.18 $

So, from equation (2) , 0.13x +0.18y=6.66 (3)

on applying substitution method in equation (1) and (3).

We get, x=18 stamps and y=24 stamps.

answer: -8.2562234e+13