If 20 men can build a wall 56 metres long in 6 days, what length of a similar wall can be built by 35 men in 3 days?
Answer
Answer (as printed):
Explanation
Let the required length be x metres. More men, More length built (Direct Proportion) Less days, Less length built (Direct Proportion) Men 20 : 35 :: 56 : x Days 6 : 3 (35 × 3 × 56) ∴ (20 × 6 × x) = (35 × 3 × 56) ⇔ x = = 49. 120 Hence, the required length is 49 m.
Explanation as extracted from the printed page; notation may be imperfect.