Question

How much does it cost for an adult whose consultation takes $9$ minutes?

• A. $70$ dollars
• B. $72$ dollars
• C. $75$ dollars
• D. None of these

Answer 1

The correct option is B $72$ dollars

In the graph

Equation of line of student from $(0,0)$ and $(8,64)$

$y=\frac{64}{8}\left(x\right)$

$y=8x$---(1)

Here in above equation y represents cost and x represent time(in minute)

To find the cost of student for 9 minutes putting $x=9$ in eq (1)

$y=72$

Here y as cost Hence the cost for 9 minutes is $72$ dollars for student