Jaslyn, Hazel and Betty each sold an equal number of scones. Jaslyn collected a total of $78.20 from selling 7 chocolate scones and some vanilla scones. Hazel collected a total of $86.60 from selling 13 chocolate scones and some vanilla scones. How much did Betty collect if she sold only vanilla scones?
Hazel collected more money than Jaslyn from the sale of the scones but the number of scones sold by each girl was the same. This shows that each chocolate muffin is higher priced than each vanilla muffin. 

Amount that Hazel collected more than Jaslyn
= 86.60 - 78.20
= $8.40

Number of more chocolate scones that Hazel sold
= 13 - 7
= 6

Extra amount collected from the sale of each chocolate muffin
= 8.40 ÷ 6
= $1.40

Total extra amount collected from the sale of 7 chocolate scones
= 7 x 1.40
= $9.80

If Jaslyn sold only vanilla scones, she would collect $9.80 less than her original amount.

Amount that Betty collected if she sold only vanilla scones
= 78.20 - 9.80
= $68.40

Answer(s): $68.40