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.
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 = a2 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:
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(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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Let’s fill up the table below
This year the students of Nandlal H.S school have passed 85% in Bengali, 70% in maths and 65% in both subject scoring A+. If the number of students are 120 then let’s work out how many students
(i) got A+ in both subjects
(ii) got A+ only in maths
(iii) got A+ in Bengali
(iv) did not get A+ in both subjects
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