A factory manufactures two types of screws A and B, each type requiring the use of two machines, an automatic and a hand-operated. It takes 4 minutes on the automatic and 6 minutes on the hand-operated machines to manufacture a packet of screws ‘A’ while it takes 6 minutes on the automatic and 3 minutes on the hand-operated machine to manufacture a packet of screws ‘B’. Each machine is available for at most 4 hours on any day. The manufacturer can sell a packet of screws ‘A’ at a profit of 70 paise and screws ‘B’ at a profit of Rs 1. Assuming that he can sell all the screws he manufactures, how many packets of each type should the factory owner produce in a day in order to maximize his profit ? Formulate the above LPP and solve it graphically and find the maximum profit.
let the no.of packets of screw 'A' manufactured in a day be x and that of screw B be y
Therefore
Item | Numbers | Machine A | Machine B | Profit |
Screw A | x | 4 minutes | 6 minutes | Rs 0.7 |
Screw B |
y | 6 minutes | 3 minutes | Rs 1 |
Max time available |
4hrs = 240 min | 4hrs-240 min |
Thus , the constrauals are
and Total profit
so our LPP will be
Max
subject to the consrauals
and
Now,
x | 0 | 60 |
y | 40 | 0 |
x | 0 | 40 |
y | 80 | 0 |
ploting points an graph, we get the fearible region OABC as shown
Corner points | Value of |
C(0,40) | |
B(30,20) | |
A(40,0) | |
O(0,0) |
Hence profit will be maximum if comparing produces 30 packets of screw A and 20 packets of screw B and maximum profit is 41 rupees.