Answer:
-4 and 10
Step-by-step explanation:
It is 7 units from 3 not 3 the number itself

Here we go ~
The air plane descends 15 feels every 1.45 seconds, so it's unit rate is :

Now we have to calculate the descent in 3.5 minutes ~


So, the airplane descends 2172.41 feels in three and a half minutes ~
Cost of fuel = 30% of $400 000 = 30/100 x 400000 = $120 000
Fuel amount = $120 000/$1.5 = 80 000 liters
new cost of fuel = 80000 x $1.6 = $144 000
increase in cost = 144000 - 120000 = $24000
So the increase in petrol price increases the operating cost by $24000