Since we know that there is a 1 in 12 chance that the spinners will land on "4" and "C" and we know the total amount of spins is 240, we can find one twelfth of 240. To do so, you multiply 240 by 1/12 which is the same as 240/12. This can be simplified to 20 through division. Therefore, the answer is 20 times.
