Question

Lee is sending out 32 birthday party invitations. She gives 5 invitations to her mom to give to family members. Lee mails a third of the rest, and then she takes a break to walk her dog.

a. Write a numerical expression to describe how many invitations Lee has already mailed.b. Which expression matches how many invitations still need to be sent out?
1) 32 - 5 - 1/3(32 - 5)
2) 2/3 x 32 - 5
3) (32 - 5):1/3
4) 1/3x(32-5)

Answer 1

(a)
`(32-5)/(3)`; 9 mails.

(b) (1).
`32-5-(1)/(3)(32-5)`

Explanation:

We have been given that Lee is sending out 32 birthday party invitations. She gives 5 invitations to her mom to give to family members. The invitations left after 5 invitations would be
`32-5`.

Lee mails a third of the rest. The number of invitations sent by Lee would be
`(32-5)/(3)`.

`\text{Invitations mailed by Lee}=(32-5)/(3)`

`\text{Invitations mailed by Lee}=(27)/(3)`

`\text{Invitations mailed by Lee}=9`

Therefore, Lee has already mailed 9 invitations.

(b). To find the number of invitations that still need to be sent out, we will subtract the number of mails sent by Lee and her mother from 32 invitations.

`\text{Number of invitations that still need to be sent out}=32-5-(1)/(3)(32-5)`

Therefore, our required expression would be
`32-5-(1)/(3)(32-5)` and 1st option is the correct choice.

Answer 2

a.
`(1)/(3)(32-5)`

b.
`32 - 5 - (1)/(3)( 32 - 5 )`

Explanation:

a. Given,

The total invitation to send out initially = 32,

The number of invitation send to mother = 5,

So, remaining invitation = 32 - 5

Again, the invitation which are already mailed

= 1/3 of the remaining invitation,

`=(1)/(3)(32-5)`

b. Thus, the final number of invitation which need to send out

= Remaining invitation after giving to mother - invitation which are mailed

`= 32 - 5 - (1)/(3)( 32 - 5 )`

OPTION 1) is correct.