Answer:
10 stickers.
Step-by-step explanation:
Let's say that Mandy has m stickers, and Priscilla has p stickers.
m = 1/4p
6/5(m + 28) = p + 28
6/5(1/4p + 28) = p + 28
1/4p + 28 = 5/6p + 23 and 1/3
5/6p - 1/4p = 28 - 23 and 1/3
10/12p - 3/12p = 84/3 - 70/3
7/12p = 14/3
p = (14/3)(12/7)
p = 8
At the beginning, Priscilla had 8 stickers. That means that Mandy had 1/4 * 8 = 8 / 4 = 2 stickers.
So, in the packet, there were 8 + 2 = 10 stickers.
Hope this helps!