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