Question

14 POINTS!

Answer 1

180 minutes to finish

Answer 2

What fraction of side per hour

you
= 1 side / 2 hrs
= 1/2 side/hr

brother
= 1 side / 3 hrs
= 1/3 side/hr

combined rate
= 1/3 + 1/2
= (1/3)(2/2) + (1/2)(3/3)
= 2/6 + 3/6
= 5/6 side/hr

after 2 hrs you are done with your side, brother has 2*(1/3) = 2/3 done.
3/3 - 2/3 = 1/3 left to paint

(1/3 side)*(6 hr / 5 side) = 2/5 hr
2/5 hr * 60 min/hr = 24 min