You have to add the according numbers bcoz the a and b are just adding up
3+6 9
Priya makes 9.8 an hour so that means that Siobhan makes 9.31 the hour
I believe the answer is 120. 3 5/6 turns into 3.833 when turned into a decimal. 3.833 would round up to 4 which is the nearest whole number. 34 3/7 would turn into 34.4285 as a decimal which turns into 30 when rounded to the nearest ten.