Question of the Day

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6/1

Nov

14

2012

331,116 responses

Question of the Day Statistics
	Number Answered
Correct	111,969
Incorrect	219,147

33% correct

Mathematics > Standard Multiple Choice

Read the following SAT test question and then click on a button to select your answer.

The length of a rectangle is increased by 20% , and the width of the rectangle is increased by 30% . By what percentage will the area of the rectangle be increased?

Hint

If the original length of the rectangle is and if it is increased by 20% , in terms of , it will be 12 times l .

Question of the Day

Can you answer today's question?

Register Next Tests:
6/1

Nov

14

2012

331,116 responses

Question of the Day Statistics
	Number Answered
Correct	111,969
Incorrect	219,147

33% correct

Mathematics > Standard Multiple Choice

Read the following SAT test question and then click on a button to select your answer.

The length of a rectangle is increased by 20% , and the width of the rectangle is increased by 30% . By what percentage will the area of the rectangle be increased?

Answer

Let and be the original length and width of the rectangle, respectively. If we denote by and the new length and width of the rectangle, respectively, then we have:

L = l + ((20 over 100) times l) = 1.2 times l and W = w + ((30 over 100) times w) = 1.3 times w

So, the new area will be:

A = L times W = (1.2 times l) times (1.3 times w) = 1.56 times (l times w)

1.56 times (l times w) = (l times w) + ((56 over 100) times (l times w))

where ( l times w ) is the original area of the rectangle.
So the area is increased by 56% .