Question

6

Pens cost 20p each.
Rulers cost 60p each.
Saj buys some pens and some rulers.
He buys 8 rulers.
The total cost is £10
How many pens does he buy?

Answer 1

26 pens

Explanation:

Let P and R be the numbers of Pens and Rulers Saj purchases.

The cost of P Pens and R Rulers:

Pens = P(20p)

Rulers = R(60p)

P(20p) + R(60p) = £10

P(0.20) + R(0.60) = 10

R = 8

P(0.20) + (8)*(0.60) = 10

P(0.20) + 4.8= 10

P(0.20) = 5.2

P = (5.2/0.20)

P = 26 pens

CHECK:

8 Rulers = 8*(60p) = 480p

26 Pens = 26*(20p) = 520p

Total = £10