Question

Christina collects stamps. She has 47 stamps in all. She has 20 stamps from Europe. The number of African stamps is 2 times the number of Asian stamps. How many stamps from each of these three continents does she have? Use reasoning to write this as a numerical expression.

Answer 1

20 stamps from Europe

18 stamps from Asia

9 stamps from Afrca

Explanation:

Let

x=number of Europe stamps

y=number of Africa stamps

This implies that

2y=Number of Asia stamps

She has 47 stamps in all implies that

x+y+2y=47

20+3y=47

3y=47-20

3y=27

`(3y)/(3)= (27)/(3)`

y=9