Jen & Jakie are 33miles apart on a calm lake paddling toward each other. Jen paddles at 4miles per hours, while Jakie paddles at 7miles per hour. How long will it take them to meet?

recall that rate is just distance travelled over time, or

v = d/t
let x = time required for them to meet
thus since they are paddling toward each other, we add their rates and multiply it by the time required and equate this distance to 33:
(4 + 7)x = 33
11x = 33
x = 3 hours

hope this helps~ :)