Need help with macroecon

Returns to scale in production: Do the following production function exhibit increasing, constant, or decreasing returns to scale in K and L? (Assume A is some fixed positive number.) (a) Y = K1/4[1/2 (b) Y = AK2/5 12/3 (c) Y = K1/2[1/2 (d) Y = K+L (e) Y = K2/3 [1/3 + A (f) Y = K2/31/3 - A