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Altamash

· started a discussion

· 1 Months ago

or you can simply apply----a+b+ab/100

Question:
If the length and breadth of a rectangle are changed by + 20% and – 10% respectively. What is the percentage change in area of rectangle? 
Options:
A) 8 % increase 
B) 8% decrease 
C) 20% increase 
D) Data insufficient
Solution:
Ans: (a) l × b = area

1 × 1 = 1

1.2 × 0.9 = 1.08

So there is 8% increase in the area of rectangle. 

Knowledge Expert

· commented

· 1 Months ago

Dear Student, Please refer the below solution, Initial area = L*B Now given that length is increased by 20 % Therefore new length = L + 20L/ 100 = 1.2 L Similarly as breadth is decreased by 10% New breadth = B - 10B / 100 = 0.9 B New Area = 1.2 L * 0.9 B = 1.08 LB Change = (1.08 LB - LB) * 100 / LB % = 8% increase Team TR

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