45 workers work 8 hours to dig a hole 30 meters deep. How many extra workers should be hired to dig another hole 30 meters deep by working for 6 hours?  Choose the correct answer
A) 10
B) 15
C) 20
D) 25
E) 30

Rationale: "45 workers * 8 hours / 30 meters = x * 6 / 30 x = 60 total workers 60 - 45 = 15 new workers the answer is b ."
Answer: B