If the length of a rectangle is increased by 20% and it’s breadth is decreased by 20% then it area________?
A. Increased by 4%
B. decreased by 4%
C. Decreased by 1%
D. Remains unchanged
Explanation:
Let length = x metres and breadth = y metres, then area =(xy)
New length =(120/100x)m = 6x/5 m
New breadth =(80/100 y)m
New area =(6x/5 x 4y/5)m2 = (24/25 xy)m2
Decreased in area =(xy – 24/25 xy)m2= xy/25 m2
Decreased % =(xy/25 x 1/xy x 100)% = 4%