Question

A knife is twice the cost of a spoon. 8 spoons and 12 knives cost £46.08. Work out the cost of 1 knife.

Answer 1

So most people do Simultaneous equations and ratios (had this question in a test today)

I did 12x2=24 this is to make them equal to spoons

Then 24+8=32 so theres 32 spoons

Then 46.08 divided by 32=1.44

So 1 spoon costs £1.44

Then 1.44x2=2.88

So 1 knife costs £2.88

Answer 2

A knife costs £2.88.

Explanation:

Create two equations using what you know to show the problem.

k = 2s

12k + 8s = 46.08

Substitute the first equation in for k, then isolate s to find how much spoons cost.

12(2s) + 8s = 46.08

24s + 8s = 46.08

32s = 46.08

s = 1.44

A spoon costs £1.44. To find the price of a knife, double the cost of a spoon:

1.44 * 2 = 2.88

A knife costs £2.88.