State Whether the Following Production Functions Exhibit Increasing, Constant, or Decreasing

Essay

State whether the following production functions exhibit increasing, constant, or decreasing returns to scale in K and L.
(a) $Y = K ^ { 1 / 3 } L ^ { 1 / 2 }$
(b) $Y = K ^ { 2 / 3 } L$
(c) $Y = K ^ { 1 / 2 } L ^ { 1 / 2 }$