Drove 238 miles and used 27.3 litres of petrol: find upper bound for consumption per mile, considering measurement errors

Question

$X$ drove $238$ miles, correct nearest mile. They used $27.3$ litres of petrol, to the nearest tenth of a litre.

$\text {Petrol Consumption} =$$\text {Miles}\over \text {Petrol Used}$

Work out the upper bound.

---

I used $238.5\over 27.35$ to get $8.72 (2dp)$

however the book states the answer is $8.75$

Am I wrong, and how? Or is it simply an error on the book's behalf?

Thanks.

Answer 1

PetrolConsumption is maximized when PetrolUsed is minimized.

$$\frac{238.5}{27.25} \simeq 8.75 $$