Sarah painted 5/9 of a wall. Alex painted 3/7 of a wall, if their paintings did not overlap, how much of the wall was left to be painted?

Answer 1

1 - 5/9 - 3/7

= 1 - 35/63 - 27/63

= 1 - 62/63

= 63/63 - 62/63

= 1/63 left to paint

= about 0.015873 = about 1.6% left to paint