Last year He was 7 years old.
His father is 4 times the age 7 x 4 = 28
Last year his dad was 28, so this year he is 29.
Combined age this year = 29 + 8 = 37
51 - 37 = 14 years
14/ 2 people = 7 years
8 + 7 = 15
29 + 7 = 36
15 + 36 = 51
It will take 7 years.
Let 
be the speed of train A, and let's set the origin in the initial position of train A. The equations of motion are
where 
are the positions of trains A and B respectively, and t is the time in hours.
The two trains meet if and only if 
, and we know that this happens after two hours, i.e. at 
Solving this equation for v we have
So, train A is travelling at 105 km/h. This implies that train B travels at
Answer:
2.25
Step-by-step explanation:
You could just use a calculator.
Translation does not affect length.
So the length of E'F' is 5 units.
