A basketball player made 3 out of 4 free throws she attempted. She wants to know how many consecutive free throws more in a row she would have to make to raise her overall percent of successful free throws to 90%.
Call x the number of additional successful free-throws
So we have
3 + x
____ = .90 cross-multiply
4 + x
3 + x = .90 ( 4 + x) simplify
3 + x = .3.6 + .90x subtract 3, .90x from both sides
.1x = .6 divide both sides by .1
x = 6 = number of additional successful free-throws