Answer: 75
Step-by-step explanation
After the exchanges happen, the ratio of chocolates to sweets for Alice is 5:2.
Multiply both parts by 10 to get the equivalent ratio 50:20.
It tells us that Alice ends up with 50 chocolates paired up with 20 sweets.
x = number of chocolates Alice started with
x/3 = number of chocolates given to Betty
2x/3 = number of chocolates Alice has left over
2x/3 = 50
2x = 50*3
2x = 150
x = 150/2
x = 75