Sean has a collection of coins. One tenth of the coins are from Europe. Thirty-two hundredth are from Asia. The rest are from Africa. Write a decimal to show the total part of the coins that are from Europe or Asia.

Lets write each part, the total will be x:

(1/10) x = Europe

3200 = Asia

x - (1/10) x - 3200 = Africa

Europe + Asia = (1/10) x + 3200 = x/10 + 3200

= (320x + 1) / 3200

that would be expressed as a fraction, and depends on the total of coins, x