Mathematics for IGCSE & O level - Ratio And Proportion (Section 1 - No. 28)
If the ratio of the sides of a rectangle is 4:9, and the perimeter is 52 cm, what is the length?
12 cm
18 cm
20 cm
24 cm
Wyjaśnienie
2(4+9)=26. 52/26 = 2. So length is 9*2 = 18