posted by John on .
The circumference of a circle is 4 times the circumference of a circle with a radius 1 unit less. What is the radius of each circle?
radius of larger circle --- r
radius of smaller circle --- r-1
circumf of large ---- 2πr
circumf of smaller = 2π(r-10
but 2πr = 4(2π(r-1))
2πr = 8πr - 8π
divide each term by π and rearrange equation
-6r = -8
r = 8/6 = 4/3
larger has radius 4/3
smaller has radius 1/3
I will leave the checking up to you,
HATS OFF ! Amazing is a less adjective for you. Thank you.