A bag of marbles can be shared equally among 3, 4, 5, 8 or 10 people with none left over. What is the smallest number of marbles that could be in the bag? Please help this is due at 11:59

Astuntman jumping off a 20-m-high building is modeled by the equation h=20-5t^2, where t is the same in seconds. a high-speed camera is ready to film him between 15m and 10m above the ground. for which interval of time should the camera film him?