please people i need your help.

Question

*Equal squares as large as possible are drawn on a rectangular board measuring 50 cm by 70 cm. Find the size of the square.

Answer 1

assuming you mean to cover the entire board, then since
GCD(50,70)=10
The largest square which will work has side 10

Answer 2

And what is the minimum number of squares can be drawn on a rectangular board.

Do you mean 10 cm or there is no unit?

Answer 3

10 cm.