Matrix M shows the one-way fares for four commuter train routes. Suppose the rail service lowers all fares by 15%. Which formula shows how to find the matrix that would display the new fares?

Route 1 $6.25 Weekday $4.75 Weekend

Route 2 $7.50 Weekday $5.25 Weekend = M
Route 3 $4.75 Weekday $3.50 Weekend

Route 4 $8.00 Weekday $5.75 Weekend

Question

Matrix M shows the one-way fares for four commuter train routes. Suppose the rail service lowers all fares by 15%. Which formula shows how to find the matrix that would display the new fares?

Route 1   $6.25 Weekday    $4.75 Weekend

Route 2   $7.50 Weekday    $5.25 Weekend   = M
 Route 3   $4.75 Weekday    $3.50 Weekend

Route 4   $8.00 Weekday    $5.75 Weekend

kainui · Answer

Since all fares are lowered, multiplying the matrix M by just a single scalar, .15 will adjust all the prices.