A projectile is fired directly upward. The compound inequality 89 – 9.8t < 10.6 or 89 – 9.8t > 20.4 represents a projectile’s velocity that is less than 10.6 m/s or greater than 20.4 m/s. Solve the compound inequality.

The solution to the inequality 89 – 9.8t < 10.6 is
.

The solution to the inequality 89 – 9.8t > 20.4 is
.

To determine when the projectile hits the ground, solve 89 – 9.8t = 0 for t. Rounding to the nearest whole second, t is about
seconds.

The viable solution set is