Define Given
We are given the following information:
• 174 paving stones total (examined)
,
• 16, paving stones ,cracked
,
• 21, paving stones ,discolored
,
• 3, paving stones ,both cracked and discolored
We are trying to find the probability of paving stones that are not cracked.
Solving
Since we know from our given that 16 paving stones were cracked plus an additional 3 paving stones were both cracked and discolored, the total amount of cracked stones out of the 174 paving stones is equal to 19.
Therefore, we know that there will be 155 paving stones that aren't cracked. In order to find the probability, we will need to divide this number over the total amount of stones present:
If we evaluate this fraction, we should obtain our answer.
Answer
The probability that a paving stone isn't cracked is equal to 0.890805.