Mario makes 6 free throw shots out of his first 10 attempts. what is the least number of consecutive shots mario must make to increase his percentage from 60% to at least 70%?

Mario made 6 free throw shots out of 10 attempts which means that his accuracy is
6/10 = 0.6 = 60%
To increase it from 60% to 70%
We let x as the number of consecutive shots Mario must make
(6 + x) / (10 + x) = 0.70
Solving for x
6 + x = 7 + 0.70x
x - 0.70x = 7 - 6
0.30x = 1
0.30x/0.30 = 1/0.30
x = 3.33 ~ 4
He must make at least 4 shots