Question

Steven has 14 steel balls of equal weight. If he puts 9 of them in one pan of a pan balance and the rest along with a weight of 20 grams in the other pan, the pans balance each other. What is the weight of one steel ball?

Answer 1

5 grams

Explanation:

Let x represent the weight of each ball.

9 steel balls in one pan would then have a weight of 9x.

This leaves 14-9 = 5 balls for the other pan; they have a weight of 5x. Additionally we add 20 grams to this pan; this gives us 5x+20.

This gives us the equation

9x = 5x+20

Subtract 5x from each side:

9x-5x = 5x+20-5x

4x = 20

Divide both sides by 4:

4x/4 = 20/4

x = 5

Answer 2

9b=5b+20

4b=20

b=5 grams