Answer:

Step-by-step explanation:
Given a basket, the probability of a ball to end there is
(because there are m baskets).
Then, the probability of a ball to end in other basket is
.
Finally, the probability of the basket to remain empty after n throws is

This last is because, given n independets events with probability p, the probability for all of them to happen is
. In this case 
You would first subtract 2 from both sides. Then add n to both sides. Then you would divide 16 by 2 and you would get n=8
Its called equivalent fractions when you have a whole fraction
Answer:
315
Step-by-step explanation:
If 70 children is 2 parts, one part is 35
35*9 is 315