Find the area of the figure

60 ft

Separate into 2 rectangles and add their areas together!

Vertical rectangle area: 10 x 3 = 30 ft

Horizontal rectangle area: 10 x 3 = 30 ft

Area of entire thing: 30 + 30 = 60 ft

answer: all of the odd numbers were opened

the first person was the one that was opening all of the lockers. since one is odd, this causes all of the odd number lockers to be opened in the end.