Hell please please please

The data in the table represent the height of an object over time. which model best represents the data? height of an object time (seconds) height (feet) 05 1 50 2 70 3 48 quadratic, because the height of the object increases or decreases with a multiplicative rate of change quadratic, because the height increases and then decreases exponential, because the height of the object increases or decreases with a multiplicative rate of change exponential, because the height increases and then decreases

Can any one me with the answers to these questions asap?

The sum of the speeds of two trains is 720.2 mph. if the speed of the first train is 7.8 mph faster than the second train, find the speeds of each.