There are 30 cars in my building's parking lot. All of the cars are red or white, and a car can have either 2 doors or 4 doors. 1/3 of them are red, 50% of them are 4-door, and 8 of them are 2-door and white. How many of the cars are 4-door and red?

Firewolf Aug 25, 2018

#1**+2 **

Make a two-way table as follows:

RED WHITE

2-DOOR 7 8

4-DOOR 3 12

TOTALS 10 20

So, it looks like you have 3 cars that are red and have 4 doors.

Guest Aug 25, 2018

#2**+2 **

Thanks, guest....here's another way

(1/3) are red = 30 *1/3 = 10 are red

So...20 are white

50% are 4 door = 15 are 4 door

So ....15 are 2 door

8 are 2 door and white.....so 12 are 4 door and white since we have 20 white total

And since 15 are 4 door and 12 of these are white...then 3 must be 4 door and red

CPhill Aug 25, 2018