Question

If the sum of the radius of two circles is 7 cm and the difference of their circumferences is 8 cm, thei
circumferences will be:
(a) 28cm and 18cm
(b) 20cm and 12 cm
तितमे कोई नहीं/None of these​

Answer 1

let the radius of one be x

and another 7-x. ( as thier sum)

now thier circumference

1st = 2πr= 2*22/7*x = 44x/7

2nd = 2πr= 2*22/7*(7-x)= 44*(7-x)/7= 308-44x/7

accordingly,

1st-2nd=8

(44x/7)-(308-44x/7)= 8

44x-308+44x/7=8

88x-308=56

88x=56+308

x=56+308/88

x= 4.1

I think none of these is correct