Question

Bob has B marbles in his marble collection. After Bob got another 15 marbles, he gives away 1/5 of his marbles. Write an expression for the number of marbles that Bob now has. Explain your reasoning.

Answer 1

`(B)/(5) + 3`

Explanation:

B: number of marbles

Bob got 15 marbles:
`B+15`

Bob gives away 1/5 of his marbles. So, let's multiply our first expression by 1/5

`(B+15) X(1)/(5)`

Next, apply the distributive property of multiplication

`(B)/(5) + (15)/(5)  = (B)/(5) + 3`

To the initial B marbles that Bob has, plus 15 aditional marbles he got later, we multiply it by 1/5 applying its distributive porperty to obtain the number of marbles that Bob now has