A packet of rulers has N rulers, each costing £.20 write an expression for the total cost of a pocket of rulers

I might be wrong but I did the calculations and my answer is that she put $30 aside each week and the airfare to hawaii is $660

Step-by-step explanation:

This is how I find my answer

first:

14 weeks - 9 weeks = 5 weeks

$390 - $240 = $150

$150/5 = $30 ( that is what she save per week)

then I did

$30 x 140 = 420 + 240 = $660