Mathematics for IGCSE & O level - Ratio And Proportion (Section 4 - No. 22)
A machine can produce 60 items in 4 minutes. Which of these statements is (are) true?
The machine produces 15 items per minute.
The machine produces 240 items per minute.
To produce 300 items, it will take 20 minutes.
To produce 30 items it will take 2 minutes.
คำอธิบาย
60 items / 4 minutes = 15 items/minute. 300 items / 15 items/minute = 20 minutes. 30 items / 15 items/minute = 2 minutes.