Beth drives 200 miles in 4 hours. She drives the first 18 miles at an average speed of 36 mph. Work out her average speed for th

Question

lys-0071

3 months ago

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Beth drives 200 miles in 4 hours. She drives the first 18 miles at an average speed of 36 mph. Work out her average speed for th

e rest of the journey...

Mathematics

1 answer:

Zina [12.3K] · Answer 1 · 2026-02-23T11:42:12+03:00

Beth travelled the remaining distance with an average speed of 52 mph

Solution:

Given, Beth drives 200 miles in 4 hours.

The equation for distance speed is expressed as:

$\text { distance }=\text { speed } \times \text { time. }$ --- eqn 1

Calculating time spent for 18 miles:

She completes the initial 18 miles at an average speed of 36 mph.

Distance here equals 18 miles

speed equals 36 mph

Substituting values into eqn 1 yields,

$\begin{array}{l}{\rightarrow 18 \text { miles }=36 \mathrm{mph} \times \text { time }} \\\\ {\rightarrow \text { time }=\frac{1}{2} \text { hour }}\end{array}$

Determining average speed for the remaining journey:

The distance left to cover is = 200 miles – 18 miles = 182 miles

The time spent on the remaining trip equals the total time minus the duration for the first 18 miles

$4 \text { hours }-\frac{1}{2} \text { hours }=\frac{7}{2} \text { hours }$

Inserting values into eqn 1 gives us

$\begin{array}{l}{182 \text { miles }=\text { average speed } \times \frac{7}{2} \text { hours }} \\\\ {\text { Average speed }=\frac{182}{7} \times 2=52}\end{array}$

This confirms that the average speed for the rest of the journey is 52 mph