Answer:
34 minutes
Step-by-step explanation:
Given


Required
Number of minutes left to spend (x)
Since there's only 1 minute left to spend on every other call;
Time left = x * 1
Time left = x
The required can further be calculated using:

This gives:

Subtract 6 from both sides


<em>Hence, there are 34 minutes left to spend</em>
Answer:
Option C - 420
Step-by-step explanation:
Given : Objective function, P, with the given constraints

Constraints,


To find : What is the maximum value
Solution :
First we plot the graph through the given constrains.
As they all move towards the origin the common region of the equations is given by the points (0,0), (0,12), (2,10), (4,0)
Refer the attached figure.
So, we put all the points in P to, get maximum value.






Therefore, The value is maximum 420 at (0,12)
So, Option C is correct.
Answer:
I think -7; +1
(sorry if I write this but the answer must be at least 20 characters long)