Wendy spent 1/10 of her money on 8 cookies and 3 muffins. The cost of 1 muffin
was twice the cost of 1 cookie. She bought some more cookies with 1/6 of her
remaining money, How many cookies did she buy altogether?
Let c = cookies
Let m = muffins
1/10m = 8x + 3 * 2x
m = 10x (8 + 3 * 2)x = 140x
remaining money = (m - 1/10m) = 9/10m = 9/10 * 140x = 126x
number of cookies bought later = 1/6*126x/x = 21
Total number of cookies is 8 + 21 = 29