Final answer:
To calculate the number of floor joists needed for a floor system, divide the length of the floor system by the length of each joist. None of the option is correct
Step-by-step explanation:
To calculate the number of floor joists needed for a floor system, we need to divide the length of the floor system by the length of each joist and round up to the nearest whole number.
In this case, the length of the floor system is 60', and the length of each joist is 16'. Dividing 60 by 16 gives us approximately 3.75. Since we cannot have a fraction of a joist, we need to round up to the nearest whole number, which is 4. So, we would need 4 joists to cover the width of the floor.
Therefore, the correct answer is 4 joists.
None of the option is correct