self Maths Puzzle

A solid, four-inch cube of wood is coated with blue paint on all six sides.
Then the cube is cut into smaller one-inch cubes.

These new one-inch cubes will have either three blue sides, two blue sides, one blue side, or no blue sides. How many of each will there be?

Read Solution (Total 3)

self Other Question

1*8+1=9
12*8+2=98
123*8+3=987
1234*8+4=9876
12345*8+5=98765
123456*8+6=987654
1234567*8+7=9876543
12345678*8+8=98765432
123456789*8+9=987654321
A bridge will collapse in 17 minutes.

4 people want to cross it before it will collapse. It is a dark night and there is only one torch between them.

Only two people can cross at a time.

"A" takes a minute to cross.
"B" takes 2 minutes.
"C" takes 5
and "D" takes 10 minutes

How do they all cross before the bridge collapses?