Final answer:
Amyaris had $63 when she started shopping.
Step-by-step explanation:
To find out the amount of money Amyaris had when she started shopping, we need to work backwards. Let's assume Amyaris had $x when she started. She spent one-fourth of her money on shorts, which means she spent (1/4)x dollars. After this purchase, she has 3/4 of her money remaining.
Next, she spends one-third of her remaining money on a belt, which is (1/3)(3/4)x = (1/4)x dollars. After this purchase, she has 2/3 of her money remaining. If Amyaris has $42 left after these two purchases, we can set up the following equation:
(2/3)x = 42
To solve for x, we can multiply both sides of the equation by (3/2) to cancel out the fraction:
x = 42 * (3/2) = 63
Therefore, Amyaris had $63 when she started shopping.