Mathematics for IGCSE & O level - Ratio And Proportion (Section 1 - No. 34)
The ratio of the length of a rectangle to its width is 7:3. If the width is 9 cm, what is the length of the rectangle?
15 cm
21 cm
28 cm
35 cm
설명
Length:Width = 7:3, 9 is 3*3, so 7*3 = 21