The diameter of the sphere is 60 mm which means its radius is 30mm. <span>The radius of a sphere is increasing at a rate of 5 mm/s. The formula for the radius when the time is x second would be: </span>r(t)<span>= 30+ 5x dr/dt= 5
The speed of </span><span>volume increase </span><span>of the sphere volume would be derived from sphere volume: </span>V(r)=4/3* pi * r^3<span> dV/dt= 4/3 * pi * 3r^2 * (dr/dt) =4/3* pi * 3(30)^2 * 5 = 18000 pi= 56571 mm^3/s</span>
A=12 120% of a =80% of b 120%a = 80%b 120a/100 = 80b/100 Divide through by 100 120a = 80b Divide through by 80 120a/80 = b But a=12 120x 12/80 = b 18 = b b = 18
