Answer:
1.30$
Step-by-step:
Since they sell their cookies for 1/3 of the price for the last 15 minutes, cookies go on sale at 8:45.
Laura bought them at 8:30, and did not get a discount.
She bought 3 cookies for 65 cents each. That's 3 x 65 = 195 cents.
Had she waited 15 minutes, she would have gotten a discount of 1/3 off.
195 cents x (1/3) is 65.
195 - 65 = 130 cents.
130 cents or 1 dollar 30 cents.