If nCk represents the number of ways k parts can be chosen from a pool of n, the probability of interest is the complement of the probability of selecting all good parts.
1 - (167C3)/(170C3) = 42,085/804,440 ≈ 0.0523
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nCk = n!/(k!(n-k)!)
You peace in the 6 the same time
Answer:

Step-by-step explanation:
If the figures are similar, then the angles are the same. So that means that angle H is equal to angle D (you can count he little arcs in the angle to find it's matching partner). Since this is true:

Which is the same as
. Solve for x by dividing both sides by 4:

Finito.