Answer:
There are 25 people in the group
Explanation:
25.50 x 25 = 637.5 (-$7.5 of discount = 25 x 0.15=3.75)
=25 people discount, the discount was applied twice.
The only number showing for 630 is 22.50 x 28
We subtracted $2.75 in error 22.50 x 28 = 630
28/3 = 9 = 9/2 = 4.5 (28-4.5)
25.25 x 25 =$631.25
= 5 people didn't receive 0.25 discount.
OR only 0.25 was applied for 12 people.