Find number abc
If a8c53 - aabca = 5891 find number abc. Multiple solutions may exist.Correct answers: 1
#brainteasers #math

Ballpen in space
When NASA first started sending up astronauts, they quickly discovered that ballpoint pens would not work in zero gravity.
To combat the problem, NASA scientists spent a decade and $12 billion to develop a pen that writes in zero gravity, upside down, underwater, on almost any surface including glass and at temperatures ranging from below freezing to 300 C.
The Russians used a pencil.