A certain number of workers can do a work in 25 days. If there were 10 workers more it could be finished in 10 days less. How many workers are there?	Choose one.
A) 15
B) 30
C) 28
D) 24
E) 32

Rationale: number of workers = 10 * ( 25 - 10 ) / 10 = 15 answer is a
Answer: A