maths
posted by Dalcy on .
a box containing pens,nickels,and dimes has 13 coins with a total value of 83 cents.how many coins of each type are in the box?

number of pennies  p
number of nickels  n
number of dimes  13pn
p + 5n + 10(13pn) = 83
p + 5n + 130  10p  10n = 83
9p  5n= 47
9p + 5n = 47 > n = (479p)/5
since both p and n have to be positive integers
0 < p < 5 and 0 < n< 10
try p=1 , n is a fraction
p = 2, n is a fraction
p=3 , n = 4
p = 4 , n is a fraction
so p = 3, n = 4 and subbing back, dimes = 6
check" 3(1) + 4(5) + 6(10) = 83