Answer:
8.33 gallons
Step-by-step explanation:
Given: A car's fuel economy is 30 mpg. a warning light is displayed if the remaining distance that can be driven before the car runs out of gas drops below 50 miles.
To Find: initially the car has 10 gallons of gas. how many gallons, g, can be used before the warning light comes on.
Solution:
Total fuel in car
![=10\text{g}](https://img.qammunity.org/2019/formulas/physics/high-school/9xt9809t1ocynskg8ao70xk54goog4kmbg.png)
fuel economy of car
![=30\text{mpg}](https://img.qammunity.org/2019/formulas/physics/high-school/cp447afv4bdrjj7amx5019s9uq9s4bssdd.png)
fuel required to ride 30 mile
![=1\text{g}](https://img.qammunity.org/2019/formulas/physics/high-school/t9tawt3f3x54ns8e29ylqvl38pcn73apyo.png)
fuel required to ride 1 mile
![=(1)/(30)\text{g}](https://img.qammunity.org/2019/formulas/physics/high-school/zmjfhpkf6pn9spf7kj9dseq27hinux6frl.png)
Now,
Fuel required to ride 50 miles
![=50*(1)/(30)\text{g}=(5)/(3)\text{g}](https://img.qammunity.org/2019/formulas/physics/high-school/eabma33yle2kva5oki6lvj3h987tfj5rgu.png)
fuel left in car when warning light is displayed
![=\text{Fuel required to ride 50 miles left}](https://img.qammunity.org/2019/formulas/physics/high-school/hufzv7gbzd5xy61s8ldd4b0louu286p9m7.png)
![=(5)/(3)\text{g}](https://img.qammunity.org/2019/formulas/physics/high-school/tz6rnaw78chdoj0irctgx244r1881dak5a.png)
Amount of fuel that can be consumed before warning light dislays
![\text{Total fuel}-\text{fuel left when warning light displays}](https://img.qammunity.org/2019/formulas/physics/high-school/2txuglax88rsin7pi04yhbrjgoazs3joch.png)
![10-(5)/(3)](https://img.qammunity.org/2019/formulas/physics/high-school/ntoyrypxcdyei9w2z20ujp0sbhby4fcpja.png)
![8.33\text{g}](https://img.qammunity.org/2019/formulas/physics/high-school/ivnu3onzyhv3aw7mhghmpw9czul82gxcki.png)
8.33 gallons fuel can be used before warning light comes on