Complementary angles add up to 90o.
The complement of 21 is 90 - 21 = 69
(-10= xy + z ) (-z)
(-10-z = xy ) (1/y)
-10/y - z/y = x
x = -(10+z)/y
2825/1250 = 2.26
2.26 is the answer i think
the probability of picking a friend playing basketball would be 0.07%
