The boy girl ratio in the boy-girl ratio in a school is 4 to 5. if there are 225 girls, how many students are in the school? ?

Afootball quarterback has two more chances to throw a touchdown before his team is forced to punt the ball. he misses the receiver on the first throw 25% of the time. when his first throw is incomplete, he misses the receiver on the second throw 15% of the time. what is the probability of not throwing the ball to a receiver on either throw?