2015 · Q78
The area of a trapezium is 336 {cm}² . If its parallel sides are in the ratio 5 : 7 and the perpendicular distance between them is 14 cm, then the smaller of the parallel sides is
Elementary MathematicsMensuration
- A20 cm
- B22 cm
- C24 cm
- D26 cm
Explanation
This tests the trapezium area formula: (1/2)(sum of parallel sides)(height). Let the sides be 5k and 7k; then (1/2)(12k)(14) = 84k = 336, so k = 4. The smaller parallel side is 5k = 20 cm. Option (b) 22 cm would come from an arithmetic slip in solving for k. Hence option (a).