Posted by **John** on Tuesday, August 19, 2014 at 10:34pm.

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?

- Math -
**Reiny**, Tuesday, August 19, 2014 at 10:40pm
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,

- Math -
**John**, Tuesday, August 19, 2014 at 10:50pm
HATS OFF ! Amazing is a less adjective for you. Thank you.

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