solve this problem

Question

Taylor bought 12 more pencils this month than last month. taylor paid $2.88 last month and $7.20 this month for the pencils. Assuming the situation is proportional, how many pencils did she buy?

Answer 1

She bought N pencils last month for 288, as the amount is in pennies.

This month she bought N+12 for 720.

288/N = 720 / (N+12)

288(N+12) = 720N

288N + 3456 = 720N

3456 = 720N - 288N

3456 = 432N

N=8

She bought 8 pencils last month for 288, which is 36 cents each.

She bought 20 pencils this month for 720 which is 36 cents each.