Question

A crate contains 5 identical metal balls. The crate is twice as heavy as one of the metal balls. The total mass of the crate and the metal balls is 42 kg. What is the mass of a metal ball?​

Answer 1

Explanation:

x = mass of one metal ball

y = mass of the create

y = 2x (twice as heavy)

5x + y = 42 (5 balls and the crate weigh 42 kg)

we are using the first equation in the second :

5x + 2x = 42

7x = 42

x = 42/7 = 6 kg

the mass of a metal ball is 6 kg.

Answer 2

Explanation:

The crate counts as two balls ( it is twice as heavy)

so five balls + two balls weighs 42 kg

7 balls = 42 kg

1 ball then equals 6 kg