Because everybody has a head, and a fore-head.

13

12 x 12 = 144 => 1 + 4 + 4 = 9
13 x 13 = 169 => 1 + 6 + 9 = 16
25 x 25 = 625 => 6 + 2 + 5 = 13

Race car.

50:

101 divided by 2 equals 50.5

51x2= 102 so is too big to go into 101

50x2= 100 so it’s the closest you can get to 101

101-100=1 so it’s 50 and remainder 1, or... you could just do 101/2=50.5

14 years.

Let the son's present age be x years. Then, (38 - x) = x

2x = 38.

x = 19.

Son's age 5 years back (19 - 5) = 14 years.

Beetle.

In inches, snakes don't have any feet.

4.000

Mind.

Ice.

S, O, N

Wheelbarrow.