At Monday's basketball practice, John made 72% of the 50 free throws he shot. On Tuesday, he made 6 out of 10 free throws. On Wednesday, he shot 30 free throws. If his overall free-throw percentage from these three days was 70%, how many free throws did John make on Wednesday?

X = free throws made Wednesday

Total attempted free throws = Monday total + Tuesday total + Wednesday total

Attempted Total = 50 + 10 + 30 = 90

Overall free throw percentage = 70%

Total free throws made = 0.7 (90) = 63

Total free throws made = Monday's free throws made + Tuesday's + Wednesday's

Monday's free throws made = 72% of 50 =.72 (50) = 36

Tuesday's free throws made = 6

Total free throws made = 36 + 6 + x = 63

x = 63 - 36 - 6 = 21