An ice cream vendor has the following production function:

Q = 4LM

Where, Q = the number of ice cream cones produced per day, L = the number of workers hired per day, and M = the number of ice cream machines rented per day. Associated with this production function are the following marginal product relationships:

MP_L = 4M and MP_M = 4L.

1. Plot the isoquant for 320 ice cream cones per day.
2. Find the optimal combination of inputs, if the wage rate per day = $30, the ice cream machine rental per day = $150, and 320 ice cream cones are to be produced.