The inner circumference if a circular track is 220m. The track is 7m wide everywhere. Calculate the cost of putting up a fence along the outer circle at the rate of Rs. 2 per metre. `(U s epi(22)/7)`

Explanation

Let radius off inner circle is r and outer circle is R

Inner circumference = 220m

`:. 2xxpixxr = 220`

`:. 2 xx (22/7) xx r = 220`

`:. r=35m`

The track is 7m wide everywhere

`:.` Outer radius` R = 35+7 = 42m`

Outer circumference` = 2 xx pi xx R`

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