A solid metal pin is in the shape of a cylinder with a radius of r r\,r mm and a height of 4 mm.
The volume of the metal pin is 121π 121\pi\,121π mm3^33.
Find the value of rrr.
Practise OCR GCSE Maths Cylinders with exam-style questions for Foundation and Higher tier. 98 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.