Hello,
You can use this formula - [ x + y + (xy/100)]
Let X = Percentage Increase or Decrease in Length
Y = Percentage Increase or Decrease in Breadth
Use + plus or - minus sign according to increase or decrease.
So, according to question - there is 20% increase in length and 10% increase in breadth. Therefore X = +20, Y = +10
Now, put the values in the formula [x + y + (xy/100)]
= [ +20 + 10 + (+200/100)]
= [ 30 + 2 ] = 32%
Overall Increase in area of rectangle is 32%
Hope this was helpful.
Question : The length and breadth of a rectangle are increased by 10% and 20%, respectively. What will be the percentage increase in the area of the rectangle?
Option 1: 30%
Option 2: 32%
Option 3: 28%
Option 4: 33%
Question : The length and the breadth of a rectangle are increased by 15% and 10%, respectively. What is the percentage increase in the area of the rectangle?
Option 1: 25%
Option 2: 26.5%
Option 3: 27.5%
Option 4: 26%
Question : The length of a rectangle is increased by 10% and breadth is decreased by 10%. The area of the new rectangle is:
Option 1: neither increased nor decreased.
Option 2: increased by 1%.
Option 3: decreased by 2%.
Option 4: decreased by 1%.
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