Can anybody help with this question

Name each raycalculation tip: in ray "ab", a is the endpoint of the ray.

Ijust need to see how to do this. so you don’t have to answer all of them just a step by step explanation of one.

Robin spent 25% more time on his research project than he had planned he’s been an extra h ours on the project which of the following expressions could represent the number of hours rob actually spent on the project