Divide a clock face with 1 straight line so that the sum of the numbers in each part are equal.

Answer 1

The sum S of the number of the clock face is the sum of the integers 1 to 12, where
S = n(n+1)/2 = 12(12+1)/2 = 78
If S is divided in two, each half should add up to 39.

Now draw a picture of the numbers of the clock and see if you can circle numbers so that each group adds up to 39.