A rule to calculate the monthly cost of an electricity bill, in pounds (£\pounds£), is:
Multiply the number of units used by 0.15 then add 12
A customer uses 400 units of electricity in a month.
Work out the monthly cost, in pounds (£\pounds£).
The monthly cost for a different customer is £36\pounds36£36.
Work out the number of units of electricity used.
Practise OCR GCSE Maths Function Machines with exam-style questions for Foundation and Higher tier. 39 questions, matched to the OCR GCSE Maths (J560) specification and written in the written papers style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.