Question

There are four blue marbles, an unknown number of red (r marbles, and six yellow marbles in a bag. which expression represents the probability of randomly selecting a blue marble, replacing it, and then randomly selecting a red marble?

Answer 1

i think it is choice C

Explanation:

Answer 2

There are a total of
`4+r+6` marbles in the bag

The probability of choosing a blue is
`(4)/(10+r)`

The probability of choosing a red is
`(r)/(10+r)`

The probability of choosing a blue, replacing it, and then a red is

`(4)/(10+r)`×
`(r)/(10+r)` =
`(4r)/(100+20r+ r^(2) )`