Question

each time sally goes for a run, she runs 2km more than david. Sally runs seven days a week and David runs six days a week. Sally runs 22km a week more than David. How far does each run per day?

Answer 1

s: how much sally runs
d: how much david runs
7s=6d+22
s=d+2
7(d+2)=6d+22
7d+14=6d+22
d=8
s=10