Answer: - 33
Explanation:
Since, the speed of scuba diver = 2.5 feet per second
Thus, the distance covered by her in 7 second = 2.5 × 7 = 17.5 feet
But, According to the question,
She is 15.5 feet below the surface of water when she start swimming.
Thus, her total distance from the surface of water after 7 second
= Her distance from the surface when she start + the distance cover by her in 7 second
= 15.5 + 17.5 = 33 feet.
Thus, -33 represents her location relative to the surface after 7 seconds when we take surface as x-axis.