Question

A marketing firm determined that, of 200 households surveyed, 80 used neither Brand A nor Brand B soap, 60 used only Brand A soap, and for every household that used both brands of soap, 3 used only Brand B soap. How many of the 200 households surveyed used both brands of soap?

Answer 1

Answer:

those that use both soaps= 15 households

Explanation:

From the survey households use the following:

Neither soap A nor B= 80

So those that use soap= 200- 80= 120

Only soap A= 60

So those that use only soap B or both= 120- 60= 60

For every household that used both brands of soap, 3 used only Brand B soap.

So assume out of 4 households 1/4 use both soaps, and 3/4 use soap B

Therefore those that use both soaps= (1/4)*60

= 15 households