two rulers and one pencil cost £2.40 five rulers and one pencil cost £5.10 work out the cost of a ruler and the cost of a pencil .

Mathematics · College · Thu Feb 04 2021

llm

Answered on Fri Feb 18 2022

Let the cost of a ruler be x

and, cost of pencil be y

Then,
2x +y = 2.4 …..(1)
5x +y = 5.1 …..(2)

Using elimination method :

Subtracting equation (1) from (2)

We get,

5x +y - (2x +y ) = 5.1 - 2.4

5x +y - 2x - y = 5.1 - 2.4

3x = 2.7
x= 0.9

Now, putting value of x in equation (1)

2(0.9) + y =2.4

1.8 + y = 2.4

y = 2.4 - 1.8
y= 0.6

Therefore, the cost of ruler is £0.9 and cost of pencil is £0.6.