250 men work for 16 days and finish a work. How many men would do a job 3 times the previous one in 20 days?  Choose the most appropriate option
A) 700  B) 666  C) 600  D) 400  E) 800

Rationale: number of men needed to finish the required work ( variation , proportion method ) = 3 * 16 * 250 / 20 = 600 answer : c
Answer: C