A carpenter is trying to calculate the number of individual risers that a staircase will contain. The total rise of the staircase will be 11′. Assuming an individual riser height of 8″, what is the minimum number of risers that will be needed for this staircase?
A. 16
B. 18
C. 15
[D. 17]
Is it D?
yes. 11 * 12/8 = 16.5
Yes, the correct answer is D. In order to calculate the minimum number of risers needed for the staircase, divide the total rise (11 feet) by the individual riser height (8 inches).
First, convert 11 feet to inches:
11 feet * 12 inches/foot = 132 inches
Then, divide the total rise by the individual riser height:
132 inches / 8 inches/riser = 16.5 risers
Since we cannot have half of a riser, we round up to the nearest whole number to get the minimum number of risers needed, which is 17.
Therefore, the correct answer is D.
To calculate the minimum number of risers needed for the staircase, we need to divide the total rise of the staircase by the individual riser height.
Given:
Total rise of the staircase = 11 feet
Individual riser height = 8 inches
We first need to convert the total rise to inches:
Total rise = 11 feet x 12 inches/foot = 132 inches
Next, we divide the total rise by the individual riser height to get the minimum number of risers:
Number of risers = Total rise / Individual riser height
= 132 inches / 8 inches
= 16.5
Since we cannot have a fractional number of risers, we round up to the nearest whole number. Therefore, the minimum number of risers needed for this staircase is 17.
So, the correct answer is D.