Answer:
on an average, <em>2</em><em>0</em><em>H</em><em>z</em><em> </em><em>to</em><em> </em><em>2</em><em>0</em><em>k</em><em>H</em><em>z</em>

Actually Welcome to the Concept of the kinematics of a body.
Since, we know that Velocity = Distance / time
hence, V = 20/5 = 4 m/s
hence the velocity of the RC car is 4 m/s westwards direction.
The simplest way to do this is to set up equivalent fractions, like this-

=

Solve for x by using cross multiplication.
40*2.2= 88
1*x=88
x=88
Therefore, the boy weighs 88lbs.