Mathematics for IGCSE & O level - Ratio And Proportion (Section 6 - No. 6)
The ratio of the length to the width of a rectangle is 7:4. If the width is 12cm, what is the length?
16 cm
21 cm
24 cm
42 cm
Giải thích
Since the width, is 4 parts and 12 cm, therefore 1 part = 3 cm, hence length (7 parts) is 7*3 = 21 cm.