If the sum of the radius of two circles is 7 cm and the difference of their circumferences is 8 cm, theicircumferences will be:(a) 28cm and 18cm(b) 20cm and 12 cmतितमे कोई नहीं/None of these About the author Lyla
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 Reply
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