2πr:2π(r+5)=19:20
Sorry about that, there was a mistake in my previous response. Here is the correct way to solve the problem using the equation 2πr : 2π(r + 5) = 19 : 20:\n\nFirst, let's cross-multiply to get rid of the denominators:\n\n2πr × 20 = 2π(r + 5) × 19\n\n40πr = 38π(r + 5)\n\nNext, let's distribute the 38π:\n\n40πr = 38πr + 190π\n\nSubtract 38πr from both sides:\n\n2πr = 190π\n\nFinally, divide both sides by 2π:\n\nr = 95\n\nSo the answer is 95.