Mary wants to buy candies with an amount of money she has in her pocket.  we know that if she had $3.20 more money she could buy 120 candies. While if she had $2.40 less money she could buy 85 candies. What is the price per candy?

the price per candy is $0.16

and she has $16.00 in her pocket.

Step-by-step explanation:

x = the money in her pocket.

y = the price per candy

x + 3.2 = 120×y

x - 2.4 = 85×y

y = (x - 2.4)/85

=>

x + 3.2 = 120×(x - 2.4)/85 = (24x - 57.6)/17

=>

(17x + 17×3.2)/17 = (24x - 57.6)/17

17x + 54.4 = 24x - 57.6

54.4 = 7x - 57.6

112 = 7x

x = 16

y = (16 - 2.4)/85 = 13.6/85 = 0.16

final answer is : )