Sweet Treats CBE december 2016

Sweet Treats Bakery makes three types of cake: brownies, muffins and cupcakes.
The costs, revenues and demand for each of the three cakes are as follows:

Brownies Muffins Cupcakes
Batch size (units) 40 30 20
Selling price ($ per unit) 1.50 1.40 2.00
Material cost ($ per unit) 0.25 0.15 0.25
Labour cost ($ per unit) 0.40 0.45 0.50
Overhead ($ per unit) 0.15 0.20 0.30
Minimum daily demand (units) 30 20 10
Maximum daily demand (units) 140 90 100

The minimum daily demand is required for a long-term contract with a local cafe and must be met.

The cakes are made in batches using three sequential processes; weighing, mixing and baking. The products must be produced in their batch sizes but are sold as individual units. Each batch of cakes requires the following amount of time for each process:

Brownies Muffins Cupcakes
Weighing (minutes) 15 15 20
Mixing (minutes) 20 16 12
Baking (minutes) 120 110 120

The baking stage of the process is done in three ovens which can each be used for eight hours a day, a total of 1,440 available minutes. Ovens have a capacity of one batch per bake, regardless of product type.

Sweet Treats Bakery uses throughput accounting and considers all costs, other than material, to be ‘factory costs’ which do not vary with production.

On Wednesday, the mixing process is identified as the bottleneck process. On this day, only 120 minutes in the mixing process are available.

Assuming that Sweet Treats Bakery wants to maximise profit, what is the optimal production plan for Wednesday?

1) 80 brownies, 30 muffins and 100 cupcakes

2) 0 brownies, 90 muffins and 100 cupcakes

3) 120 brownies, 0 muffins and 100 cupcakes

4) 40 brownies, 60 muffins and 100 cupcakes

Can you kindly help me with this question.