MAGIC SQUARE: Calculate A-B+C
The aim is to place the some numbers from the list (2, 9, 12, 18, 23, 26, 32, 65, 68, 74) into the empty squares and squares marked with A, B an C. Sum of each row and column should be equal. All the numbers of the magic square must be different. Find values for A, B, and C. Solution is A-B+C.Correct answers: 13
The first user who solved this task is Nasrin 24 T.
#brainteasers #math #magicsquare

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.