maths problem from iGCSE textbook

A boy buys cans of pop in a shop for £10 and later finds he can buy 5 more in another shop for the same amount. How many cans did he buy?

Reply 1

Smaug123

15

Original post by goyakla

A boy buys cans of pop in a shop for £10 and later finds he can buy 5 more in another shop for the same amount. How many cans did he buy?

Unknown - we don't know how much money he had to begin with, or how much they cost in the other shop. ("The same amount" is ambiguous: did the five together cost £10, or was the cost per can the same?)

Reply 2

goyakla

OP

7

Sorry about that. Yes, the same amount means £10.

Reply 3

TenOfThem

18

Original post by goyakla

Sorry about that. Yes, the same amount means £10.

Are you sure there was no more information?

As it stands there is more than one answer

5 would work
20 would work

I think those are the only solutions

Reply 4

goyakla

OP

7

I too felt that the question lacked information. It was in an exercise which required the use of solving a quadratic to answer each question but I just could not see how to formulate a quadratic from the information given. The two solutions would bear that out but can you come up with the quadratic?

Reply 5

TenOfThem

18

Original post by goyakla

I too felt that the question lacked information. It was in an exercise which required the use of solving a quadratic to answer each question but I just could not see how to formulate a quadratic from the information given. The two solutions would bear that out but can you come up with the quadratic?