There are 15 clowns in a circus. Each clown has to act either happy or sad. Twelve of the clowns have red noses. Each of the seven happy clowns has a red nose. Five of the sad clowns have red noses. How many clowns have to act sad and do not have a red nose?

3

Step-by-step explanation:

Each of the seven happy clowns has a red nose.

This means there are (15-7) 8 sad clowns.

Five of the sad clowns have red noses.

This means out of 8 sad clowns, 5 have red noses. So the clowns that have to act sad and have red noses are (8-5) 3.

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.