Amy earns £6 for every hour she works Monday to Friday. She earns £8 for every hour she works on Saturday. One week Amy worked for 5 hours on Saturday - she earned £130 that week. How many hours did she work from Monday to Friday?

Amy worked for 5 hours on Saturday so she earned £8 x 5 = £40 on that day.

She earned £130 in total so we know she earned £130 - £40 = £90 working from Monday to Friday. 

For every hour Amy worked from Monday to Friday she made £6 so we must divide her total pay by her hourly wage to find the number of hours she worked:

£90/£6 = 15 hours 

Amy worked a total of 15 hours from Monday to Friday.