Gregg has made 40% of his free-throw shots, after attempting 20 shots at a free-throw competition. How many more consecutive shots must he make in order to increase his percentage to 50%?

Answer 1

he has made .4*20 = 8 of 20

he shoots total of 20 + x shots

8 + x = .5(20+x)
8 + x = 10 + .5 x
.5 x = 2
x = 4
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check
he has now shot 24
and has made 8+4 = 12
sure enough 12/24 = .5

Answer 2

thank you for answering the question but I don't understand how you got 10+5x?