Let, number of small, medium and large popcorn sold are s, m and l respectively.
So, s + m + l = 250 ....1)
Also, l = 2s ....2)
Total sum = $1726 = 2s + 5m + 10l .....3)
Putting value of l from 2) to 1) is :
s + m + 2s = 250
m + 3s = 250
m = 250 - 3s ....4)
Putting value of m and l in terms of s in equation 3)
We get :
2s + 5( 250 - 3s ) + 20s = 1726
7s = 1726 - 1250
s = 68
l = 136
m = 250 -3(68) = 46
Now,
Hence, this is the required solution.