If the radius of a circle is increased by 12 then the area of the circle a decreases by 25

let tadius be x
A1=pi*x^2
A2=pi*(x+x*12/100)^2=pi*(1.12x)^2
so area increases
increase in area=(A2-A1)/A1 *100=pi*(1.12+1)*(1.12-1)*x^2/pi*x^2 *100
=2.12*0.12/100=25.44
ans(b)
10 years agoHelpfull: Yes(7) No(0)
If the radius of the circle increases then the area also increases
In the options there is only one which increases so option(b)
logical right!!!!!!!(it worths only for this question)
9 years agoHelpfull: Yes(4) No(0)
If radius increases area will also increase. So in option only one option shows increase in areas so correct answer is b
8 years agoHelpfull: Yes(1) No(0)
increased by 25.44%
8 years agoHelpfull: Yes(1) No(0)
let the radius(r) = 100
then the area of the circle is(A)= pi(100)^2
upon increasing the radius by 12%, we got radius(r')=112
then the area can be given as(A') = pi(112)^2
then the change in radius from previous is (A'-A)/A*100= 25.44
ans B
8 years agoHelpfull: Yes(0) No(0)

If the radius of a circle is increased by 12%, then the area of the circle
a) decreases by 25.44%
b) increases by 25.44%
c) no change in area
d) decreases by 12%