Step 4: Interpret the answer
Now you can make an informed decision.
Should I hire the contractor and use the grant for placing the insulation in the attic, or should I do it myself?
The cost of using an approved contractor is £450. The price of installing the insulation myself is £250. Based on these values, I should choose the DIY option.
However, I may also take other factors into consideration when coming to a decision, such as the convenience of undertaking the work myself. So, the mathematical solution may be just one of several issues to consider.
Well done for working your way through this more complex problem. If there were points when you got stuck, don’t worry this happens to us all. The final section will summarise the techniques you used to help solve this last problem.