Linear Programming Question 66

Question: The maximum value of $ z=3x+4y $ subject to the constraints $ x+y\le 40,\ x+2y\le 60,\ x\ge 0 $ and $ y\ge 0 $ is

[MP PET 2002, 04]

Options:

A) 120

B) 140

C) 100

D) 160

Show Answer

Answer:

Correct Answer: B

Solution:

Given, $ P=3x+4y $

This graph has been draw from given constraints and maximum value of P will be at A or B or C . $ P _{A}={P _{(0,30)}}=3\times 0+4\times 30=120 $

$ P _{B}={P _{(20,20)}}=3\times 20+4\times 20=140 $

$ P _{C}={P _{(40,0)}}=3\times 40+0=120 $ Therefore $ {P _{\max }}=140 $ .