3+5+7 = 15 total marbles
3 are red
so she has a 3/15 reduces to 1/5 probability of picking a red one
Answer:
750
Step-by-step explanation:
because if the has 650 students and it is the greatest number
-1 / 2 + x = -21 /4
x = -21/4 + 1/2
x = (-21 + 2)/4
x = -19/4