Final answer:
The time it takes for the toy rocket and the balloon to reach the same height is 5 seconds.
Step-by-step explanation:
To find the time it takes for the toy rocket and the balloon to reach the same height, we need to set the two height equations equal to each other: -16t^2 + 90t = 10t. Rearranging the equation, we get 16t^2 - 80t = 0. Factoring out 16t, we have t(16t - 80) = 0. So t = 0 or t = 5. Since time cannot be negative, the time it takes for the toy rocket and the balloon to reach the same height is 5 seconds.