The product of three numbers is 312. Two of the numbers are 3 and 13. What is the third number?

Question

I am practising for the UKMT math challenge and I used to have a tutor and it turned out the tutor I had wasn't even good it made me worse!

Answer 1

Greetings! Lets solve this shall we ?

So we need to find three numbers that multiply to give us 312!

So let the equation of a product be set up as

xyz = 312................We are given the numbers 3 and 13 and two of the numbers such that

(3)(13)(z) = 312...............Now we can solve for the 3rd number such that

39z = 312..............Because 3(13) = 39. Now divide 39 to obtain the third number to get

z = 8

I hope this helped!