Q. 10

# The length of each arm of a square was increased by 10%. Let’s work out the increase of the percentage of area by the Rule of Three.

Answer :

Given: percentage increment of each arm of the square.

Tip:(i) if y is increased by x% then the new value of y is

(ii) Increment percentage

Let us assume that the length of each arm of the square is "a" unit length.

Using tip (i)

We calculate the new value of the arms of the square.

Therefore, the new value of the arms of the square is

We know area of square = side × side

The area of the square when the arm length was “a “units = a× a = a^{2} unit square.

The area of the square when the arm length has changed to unit is

Therefore, the increment of the area is

Therefore, the increment percentage is:

=21%

Rate this question :

(i) Rs. 2.25 out of Rs. 5

(ii) 85g out of 17 kg

(iii) 2.250 kg out of 0.72 quintal.

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