Question

Eunice and Esther are playing a game with stones. Each of them starts with 20 stones. In the first round, Eunice took 5 of Esther's stones. In the second round, Esther took 3 of Wunice's stones. If the winner is the first player to have exactly 30 stones at the end of a round, how many of Esther's stones must Eunice take in the third round to be declared the winner?

Answer 1

Let x = the stones that Eunice must take from Esther in the third round in order to be declared winner

At start,
Eu: 20
Es: 20

After first round,
Eu: 20 + 5 = 25
Es: 20 - 5 = 15

After second round,
Eu: 25 - 3 = 22
Es: 15 + 3 = 18

After third round,
Eu: 22 + x = 30

Therefore,
x = 30 - 22
x = 8 stones

Hope this helps~ :3