Please help with these 2 Q

Acircle has a radius of 12.6cm what is the exact length of an arc formed by a central angle measuring 120

Anne plans to increase the prices of all the items in her store by 5%. to the nearest cent, how much will an artist save if the artist buys a canvas and a frame that each measure 24 by 36 inches before the price increase goes into effect?

Which function has an inverse that is also a function? a. g(x) = 2x-3 b. k(x) = -9x2 c. f(x) |x+2| d. w(x) = -20