Question

When loaded with bricks, a lorry has a mass of 11600 kg. If the mass of the bricks is three times that of the empty lorry, find the mass of the bricks.

Answer 1

8700kg

Explanation:

b = mass of bricks

l = mass of lorry

b+l = total mass = 11600kg

b = 3l ==> l = b/3

substitute: b + b/3 = 11600

multiply every term by 3 to get rid of denominator: 3b + b = 34800

simplify and solve: 4b = 34800 ==> b = 8700

check: l = 8700/3 = 2900

2900 + 8700 = 11600? YES