Two carpenters, working in the same pace, can build 2 desks in two hours and a half. How many desks can 4 carpenters build in 5 hours?
Choose the correct choice from the following options
A) 2.4 . B) 3.6 . C) 4.2 . D) 8 . E) 6.4

Rationale: w = 2 desks t = 2.5 hrs rate of 2 carpenters = 2 × r rate = work done / time 2 xr = 2 / 2.5 r = 1 / 2.5 = 2 / 5 ( this is the rate of each carpenter ) work done by 4 carpenters in 5 hrs = 4 × rate of each carpenter x time = 4 × 2 / 5 × 5 = 8 desks d is the correct answer .
Answer: D