A ball is rolled up a long straight ramp…

Step 1. Velocity. $v = \dfrac{dx}{dt} = 10 - 5t$. At $1\ \text{s}$: $v = 5\ \text{m/s}$.

Step 2. When it stops. $10 - 5t = 0$ at $t = 2\ \text{s}$.

Step 3. Where. $x(2\ \text{s}) = 3\ \text{m} + 20\ \text{m} - 10\ \text{m} = 13\ \text{m}$.

Step 4. Back at the start. $3 + 10t - 2.5t^2 = 3$ gives $t(10 - 2.5t) = 0$, so $t = 4\ \text{s}$.