A. Neither increased nor decreased
B. Increased by 1%
C. Decreased by 1%
D. Decreased by 10%
C. Decreased by 1%
A=l*b
before change
A=100%lb
let l’ be the length after increment
so,
l’=l+l*10/100
l’=l*110/100
l’=l*11/10
let b’ be the breadth after decrement
so,
b’=b-b*10/100
b’=b*90/100
b’=b*9/10
so, new area will be
A’=l’*b’
A’=(l*11/10)*(b*9/10)
A’=l*b*99/100
Change in Percentage will be
A’-A
99lb/100 – 100lb/100
-1/100
or
-1% here negative show sign show % is decreasing by 1