Answer:
The answer to your question is she bought 79 large cups and 76 small cups.
Step-by-step explanation:
Data
small cups = s = $1.25
large cups = l = $2.15
total number of cups = 155
total money = $265
Process
1.- Write 2 equations to solve the problem
s + l = 155
1.25s + 2.15l = 265
2.- Solve by substitution
s = 155 - l
1.25(155 - l) + 2.15l = 265
193.75 - 1.25l + 2.15l = 265
-1.25l + 2.15l = 265 - 193.75
0.9l = 71.25
l = 71.25/0.9
l = 79
s = 155 - 79
s = 76