Given the two-factor product in, Q = 150L0.5K
0.5, wage rate of labour equals to 50 and rental
cost of capital equals to 40.
Determine the amounts of labour and capital that will minimize the cost of producing 1118
units of output.
Minimize Cost of Production.
MPKr=MPLw\frac{MP_K}{r}=\frac{MP_L}{w}rMPK=wMPL
Q=150L0.5KQ=150L0.5KQ=150L0.5K
Q=1118Q=1118Q=1118
MPk=0.5(150L)MP_k=0.5(150L)MPk=0.5(150L)
MPk=75LMP_k=75LMPk=75L
MPl=150(0.5K)MP_l=150(0.5K)MPl=150(0.5K)
MPl=75KMP_l=75KMPl=75K
w=50w=50w=50
r=40r=40r=40
∴75L40=75K50\therefore \frac{75L}{40}=\frac{75K}{50}∴4075L=5075K
3750L=3000K3750L=3000K3750L=3000K
K=1.25LK=1.25LK=1.25L
but;
1118=150L0.5K1118=150L0.5K1118=150L0.5K
1118=150L(0.5×1.25L)1118=150L(0.5\times1.25L)1118=150L(0.5×1.25L)
1118=93.75L21118=93.75L^21118=93.75L2
thus;
L=3.45=4\bold{L=3.45=4}L=3.45=4
K=1.25(4)=5\bold{K=1.25(4)=5}K=1.25(4)=5