Here is a number machine.

The machine multiplies the input by 6 and then subtracts 3.
What is the output when the input is 5?
What is the input when the output is 39?
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.