Question 1023712
A minibus operator is contracted to transport 50 Olympians from the Olympic Village to the Athletic Stadium. He has three type A minibuses and four type B minibuses available. 
A type A minibus carries 15 people and 
A type B minibus carries 10 people.
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Only five drivers are available.
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It costs $100 to operate a type A minibus and $80 to operate a type B minibus.
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He wishes to minimise the costs involved to transport the 50 Olympians.
I've completed the following:
Variables: Let a represent type A mini bus; Let b represent type B mini bus; 
Let c represent the minimum cost.
Constraints:
a <= 3 (At most 3 type A mini buses available)
b <= 4 (At most 4 type B mini buses available)
a + b <= 5 (Number of drivers)
15a + 10b <= 50 (Limit on number of passengers who can be carried in both mini buses)
Objective Function: C = 100a + 80b
Graphs - I've set the Axis to a: -1 to 3 and b: -1 to 4 and entered the above relations and constraints but don't know how to enter the formula to determine the minimum cost and I don't understand how corner points work.
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f(a)<= -a + 5
g(a)<= (-3/2)a + 5
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Draw vertical lines at a = 0 and a = 3
Not 
Draw horizontal lines at b = 0 and b = 4
Comment:: That describes the solution area.
Plot f and g in that area.  
Find their point of interception.
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Hope all that helps.
Cheers,
Stan H.
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