# If the fifth sale is on headphones, then the sale on microwaves could be earlier than the sale on

Zia on June 7, 2020

Explanation

on June 7, 2020

Hello @zia305,

The third and fourth rules combine to give us two basic diagrams:

T _ _ _ _ _ _
1 2 3 4 5 6 7

R _ _ _ _ _ T
1 2 3 4 5 6 7

This question tells us that the fifth sale is on headphones. In order to separate S from H according to rule 1, there is only one option for S, which is week 2. This allows us to place P in week 3.

T S P _ H _ _
1 2 3 4 5 6 7

R S P _ H _ T
1 2 3 4 5 6 7

We also know that L is before H.

T S P L H _ _
1 2 3 4 5 6 7

R S P L H _ T
1 2 3 4 5 6 7

This gives us only a few options for M. In diagram 1, it could be in 6 or 7, before or after R.

T S P L H R/M R/M
1 2 3 4 5 6 7

In diagram 2 it must be in spot 6, before T.

R S P L H M T
1 2 3 4 5 6 7

T is not one of the answer choices here, so the sale of microwaves can only be earlier than the sale on refrigerators, as seen in diagram 1. This is why D is correct.