What is the ratio of the distances covered by a freely falling body in the $1^{st}$,$2^{nd}$,and $3^{rd}$ seconds of its motion?

Reaction time: When a situation demands our immediate action,it takes some time before we really respond. Reaction time is the time a person takes to observe,think,and act. For example,if a person is driving and suddenly a boy appears on the road,then the time elapsed before he slams the brakes of the car is the reaction time. Reaction time depends on the complexity of the situation and on an individual.
You can measure your reaction time by a simple experiment. Take a ruler and ask your friend to drop it vertically through the gap between your thumb and forefinger. After you catch it,find the distance $d$ travelled by the ruler. In a particular case,$d$ was found to be $21.0 \; cm$. Estimate the reaction time in seconds. (in $; s$)

$A$ body is dropped from a certain height $h$ ($h$ is very large) and a second body is thrown downward with a velocity of $5 \, m/s$ simultaneously. What will be the difference in the heights of the two bodies after $3 \, s$?

$A$ man in a balloon rising vertically with an acceleration of $4.9\,m/s^2$ releases a ball $2\,s$ after the balloon is let go from the ground. The greatest height above the ground reached by the ball is...........$m$ $(g = 9.8\,m/s^2)$

$A$ ball is thrown vertically upward from the ground at time, $t=0 \,s$. It passes the top of a tower at $t=3 \,s$ and $2 \,s$ later it reaches its maximum height. The height of the tower is (Acceleration due to gravity, $g=10 \,m/s^2$) (in $\,m$)

$A$ body falls freely for $10 \ s$. What is its average velocity during this journey (in $m/s$)? (Take $g = 10 \ m/s^2$)