Answer:
Total length of wooden boards = 10 feet
As 10 is a whole number, it can't be written as an improper fraction.
Step-by-step explanation:
First we need to convert the 4 in measurement to foot.
The conversion rate is: 12 inches = 1 foot.
So we have that 4 inches is equal to 1/3 feet.
If each stair is (1/3) feet shorter than the one below, we have that:
Bottom stair = 3 feet
Second stair = 2.666 feet
Third stair = 2.333 feet
Top stair = 2 feet
The staircase have 4 stairs:
3 feet, 2.666 feet, 2.333 feet and 2 feet
Now, to know the total length of wooden boards, we just need to sum the length of each stair:
Total = 3 + 2.666 + 2.333 + 2 = 10 feet
As 10 is a whole number, it can't be written as an improper fraction.
