“Two cars, A and B, set off from the same point, at the same time, to travel the same journey. Car A travels at 55 mph and car B travels at 45 mph. If car A stops after 165 miles, how many minutes will it take car B to catch up?”
Answers after the break!
Okay. So since we’re finding an amount of time, it might be logical to first work out how long it has taken car A to travel its 165 miles. We can do this by dividing 165 by 55, since the car is going at 55 mph, and this works out at 3. So car A has been going for 3 hours.
Next, we can then use this information to work out how far car B has gone in the same amount of time. Its speed is 45 mph, so 45 x 3 = 135 miles.
This means B needs to go a further 30 miles to catch up, so we can now work out how long that will take. We know that 45 miles takes 1 hour, and that we need to go 30, so we can just work out the proportion of the hour that we need by dividing 30/45 and multiplying by 60 minutes (to get an answer in minutes and not hours).
This gives us 40 minutes, which is how long the car will take to travel those last 30 miles, and so this is our answer!
Anyone out there get it this week, or was it a bit harder?