number of creatures

Question

On a planet there are 12000 creatures with a trunk, 15000 with a tail i 20000 hairless. 8000 of them with a trunkhad a tail, 6000 with a tail were hairy, 5000 hairy ones had a trunk, 1000 of them were hairy, with a tail and a trunk. How many creatures were there on the planet?

Answer 1

30000

 

Venn diagram.

Fill in the 1000 that have hair, tail, and trunk where all three circles overlap.

 

Trunk and hair only is 5000 - 1000 = 4000

Hair and tail only is 6000 - 1000 = 5000

Trunk and tail only is 8000 - 1000 = 7000

Tail only = 15000 - 5000 - 7000 - 1000 = 2000

20000 with no hair, but 7000 + 2000=9000 are already accounted for.

So 20000 - 9000 = 11000 outside the circles

 

THe total of the bolded numbers is 30000