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)
11 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)
10 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
9 years agoHelpfull: Yes(1) No(0)
increased by 25.44%
9 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
9 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%