math
posted by John Dosley .
the ratio of the number of desktop computers sold to the number of laptops sold by a dealer is 5 to 9 if 20 desktop computers were sold then how many laptops wree sold?

Let n = number of laptops sold
5 / 9 = 20 / n
5n = 9 * 20
5n = 180
n = 36 laptops 
thanks