285 hours because there is 264 hours in 11 days and then you just add the 21 to the 264 because they're asking how many hours did each rider ride individually, not all together.
Answer:

Step-by-step explanation:
⟾Collect like terms
⟾Move the variable to the left
⟾Collect like terms again
⟾Divide both sides by -3
⟾ x = 45 ÷ 3
Hope it's helps you
700 because if it was 750 it would be closer to 800 but it is under 50
If the ratio between the sides is
, the ratio between the areas will be
and the ratio between the volumes will be 