Price list:Pencils - 10p Rulers - 30pWe know Gemma would like to buy an equal number of pencils and rulers. Therefore we can call this a 1:1 ratio. Using the price list we can see that 1 ruler and 1 pencil will cost; 30p + 10p = 40p. To make sure we do not get confused in any calculations, we have to make sure we decide if we are going to be working in £'s or p's. Let's work in p's as this is what the price list is displayed as. We know £5 is equal to 500p. Now all that is left for us to do is 500 divided by 40, which gives us 12.5. This can be done by a calculator or by counting how many times 40 (goes into) 500. As we know its impossible to have half (0.5) of a ruler and a pencil, we can see that our final answer will be 12. Gemma can buy 12 rulers and pencils with £5.