A certain number of workers can do a work in 35 days. If there were 10 workers more it could be finished in 10 days less. How many workers are there?
Options:
A) 25 B) 30 C) 28 D) 24 E) 32

Rationale: "number of workers = 10 * ( 35 - 10 ) / 10 = 25 answer is a"
Answer: A