David travels from home to work at 30 mph. At the end of the day, he travels from work back home via the same route at 40 mph. What is his average speed while travelling? (Give your answer as a simplified fraction) (None-Calculator)

First set the distance between home and work as the value x miles.The time takento get from home to work is the value y hours.The time takento get from work to home is the value z hours.Then (as timeis equal to distance divided by speed),x/30 = yandx/40 = z
The averagespeed while travelling can be calculated by taking the total distance travelled(2x miles) divided by the total time taken (y+z hours). Therefore,(Average speed)= (2x)/(y+z)Substituting yand z gives,(Average speed)= (2x)/((x/30)+(x/40))=(2x)/((40x +30x)/(1200))= 2400x / 70x= 2400 / 70= 240 / 7
David's averagespeed while travelling is 240/7 miles per hour.

DF
Answered by David F. Maths tutor

3193 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Paul buys 12 apples and 10 oranges. 12 apples cost £6. The ratio of the cost of one apple: one orange is 2:3. What is the total cost of the apples and oranges?


The new reading for James' electricity bill is 7580, and the old reading is 7510, the price per unit is 13p, how much does James have to pay for his electricity?


How do I solve 7x – 8 = -3x + 2?


Can you solve these simultaneous equations and find the values of x and y? Equation 1: 2x + y = 14 Equation 2: 4x - y = 10.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences