Math Is Fun Forum

KarenB

Guest

How many children paid £3.00?

I wonder if there is missing informatiob in this question or possibly I just don’t understand the maths!

30 children go on a trip. Some pay £5 and the rest pay £3. If the total amount paid is £110 how many paid £3?

I know the answer, but have no idea how to solve it. Please help me improve my understanding.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,640

Re: How many children paid £3.00?

Hi Karen,

Welcome to the forum.

There's a branch of algebra called simultaneous equations and you can use this to solve the problem.

Call the number paying five pounds F, and three pounds T.

You know two bits of information:

F + T = 30

and

5F +3T = 110

As the question asks for T, try to eliminate F.

From the first equation F = 30 - T

Replace F in the second like this:

5(30 - T) + 3T = 110

So now you just have to simplify the equation and find T.

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob