Answer:
Option C. $30
Step-by-step explanation:
As per question buyers are willing to pay $135 per tuning. If David demands more than this amount producer will not choose David to tune.
As we can see on first week David is willing to tune the first piano for $115,
So surplus for producer will be
135 - 115 = $20
Surplus for second week for producer will be
135 - 125 = $10
Since David is willing to tune the third and fourth piano for $140 and $175 then the producer will not choose David for tuning.
Therefore, total surplus for the producer will be $20 + $10 = $30
Option C. $30 is the correct option.
3s + 135 = 4.5s + 45
Now move the variables and coefficients
135 = 1.5s + 45
And then the numbers
90 = 1.5s
Simplify
90/1.5 = 1.5s/1.5
60 = s
Hope this helps!
0.05x4.1 would be a correct answer I think
