a) Neither increased nor decreased b) Increased by 1% c) Decreased by 1% d) Decreased by 10%
mcqs test
Solution:
Area Calculation MCQ 1 (Increase and decrease in length and breadth , to find percent change in area)
Let the length of the rectangle is = x
Breadth of the rectangle is = y
We know the are is \( = Length \times Breadth \)
i-e
\[ Area = x \times y=xy \]
Now 10% of length ;
\[ = \frac {10}{100}\times x=\frac{x}{10} \]
Since this is the increament in length so,
New length will be \( =x+\frac{x}{10}=\frac{11x}{10} \)
Similarly, 10 % of breadth;
\[ = \frac {10}{100}\times y=\frac{y}{10} \]
Since this is the decrease in breadth so,
New breadth will be \( = y-\frac{y}{10}=\frac{9y}{10} \)
New area will be = \( = New Length \times NewBreadth=\frac{x}{10}\times \frac{9y}{10}=\frac{9xy}{100}=0.09xy \)
Decrease in \( Area = Original Area – New Area \)
i-e \( Decrease in Area = xy -0.09xy=0.1xy \)
We suppose this decrease is ‘z%’ of original area ;
i-e 0.1xy = z% of xy (original area)
or \( 0.1xy= \frac{z}{100}xy \)
or
\[ z= 10% \]
So area decreased by 10 % — option d is correct!
Note: Some sources have reported option c as answer , which is miscalculated and hence, is wrong !
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Rangoonwala
Tehsildars posts has been advertised first ever by Punjab Public Service Commission PPSC. Previously these posts and still of Parwari posts are being used as political bribery or to settle some one near and dear on such lucrative posts
Jaranwala
Yes you right absolutely because a Patwari never wants his promotion to higher position, because he ‘earns’ more than his seniors and gives regular ‘share’ to high up in the chain of his seniors ‘regularly’
Rawalpindi
you right Jaranwala!