A man spent exactly $2.50 on 3-cent, 6-cent, and 10-cent stamps. if he bought ten 3-cent stamps and twice as many 6-cent stamps as 10-cent stamps, how many 10-cent stamps did he buy?

Yas

t=number of 3 cent

s=number of 6 cent

n=number of ten cent

ten 3 cent stamps (t=10)

and 2 times as many 6 cent as 10 cent (s=2n)

what is n?

find how much are 3 cent

3 times 10=30

30 cents are 3 cents

convert to cents

250-30=220

220=6s+10n

s=2n

220=6 (2n) + 10n

220=12n+10n

220=22n

divide both sides by 22

10=n

he bought 10 ten cent stamps

He bought 10 x 3 cents stamps

20 x 6 cents stamps

10 x 10 cents stamps