Just double checking my answers can someone help me out A or B? Thank you.

The graph shows the distance y, in inches, a pendulum moves to the right (positive displacement) and to the left (negative displacement), for a given number of seconds x. how many seconds are required for the pendulum to move from its resting position and return? enter your answer in the box.

In the equation sqrt(n+5)-sqrt(11-10)=1. what is the value of n

Lana's family entered a 5-kilometer race lana's average step length is about 0.5 meter how many steps will she need to take the finish