Question

An airline offers tickets on 3 routes from Atlanta: Chicago for $150, Boston for $160, and Dallas for $180, represented by the matrix [150 160 180] We can find the cost of four of each of the tickets by multiplying this matrix by one of the matrices below. Find it. (Please help @gmanyp)

Answer 1

`\left[\begin{array}{ccc}150&160&180\end{array}\right]\\\\Answer:\ B)\ \left[\begin{array}{ccc}4&0&0\\0&4&0\\0&0&4\end{array}\right]`

`Check:\\\\\left[\begin{array}{ccc}150&160&180\end{array}\right] \cdot\left[\begin{array}{ccc}4&0&0\\0&4&0\\0&0&4\end{array}\right]`

`=\left[\begin{array}{ccc}600&640&720\end{array}\right]`

Cost of four of each of the tickets:

`Chicago:4\cdot\$150=\$600\\\\Boston:4\cdot\$160=\$640\\\\Dallas:4\cdot\$180=\$720`

CORRECT :)

Answer: B