Q$1$: MIT has designed an environmentally friendly car which will run on biodiesel. Biodiesel can be produced from the Jatropha plant for about $$0\mathrm{.}2$ per liter and blended with gasoline costing $$0\mathrm{.}8$ per liter. The mixture costs $$0\mathrm{.}5$ per liter. Assume that fuel consumption is $15$ km per liter and engine performance in general is not affected by $20$:$80$ blends.

$1.$ How much money can be saved on driving $15,000$ km per year?

$2.$ How much gasoline per year is being conserved if $1$ million people use the blended fuel?

Q$2$: Often it makes a lot of sense to spend some money now so you can save more money in the future. Consider filtered water. A high$-$tech water filter costs $$50$ and can filter $7200$ ounces of water. This will save you purchasing two $20-$ounce bottles of filtered water every day, each costing $ $1.$ The filter will need replacing every six months. How much will this filter save you in a year$$s time.

Q$3$: The manufacturer of Brand A automobile tires claims that its tire can save $110$ gallons of fuel over $55000$ miles of driving, as compared to a popular competitor $($Brand B$).$ If gasoline costs $ $3$ per gallon, how much per mile driven does this tire $($Brand A$)$ save the customer.