Posted by ASDFG on .
two sides of a rectangle are 20cm and 10cm. They are increased in the ratio 2:3 and 3:7. Find the percentage increased in its area?

MATHS 
Reiny,
the way I understand the wording .....
new length/20 = 3/2
new length = 30
new width/10 = 7/3
new width = 70/3
new area = 30(70/3) = 700
old area = 20(10) = 200
increase = 500
percentage increase = 500/200 * 100% = 250% 
MATHS 
Ruby Siaosi,
herefore, new area of rectangle = xy
Original area = 20 × 10 = 200 cm2
Therefore, increase in area of rectangle = new area of rectangle  original area = 700 cm2  200 cm2 = 500 cm2
Now, percentage increase in area