Find the percent composition of each element in KMnO4

The way you want to find the percent composition would be by breaking down the problem like so:

K = atomic mass of K which is 39.098

Mn = atomic mass of Mn which is 54.938

O = atomic mass of o which is 15.999

Then you want to add 39.098 + 54.938 + 15.999 and you get 110.035 which is the molar mass for KMnO

Then you want to take each molar mass and then divide it 110.035 and multiply by 100

Ex. K = 39.098 / 110.035 and the multiply what you get by a 100

You do this for the other elements as well good luck!