Three pieces of timber 36 m, 42 m and 54 m long have to be divided into planks of the same length, What is the greatest possible length of each plank ? Choose the most appropriate option.
A) 7 m  B) 1 m  C) 2 m  D) 6 m  E) None of these
Answer   Greatest possible length of each plank = H.C.F of 36, 42, 54 = 6 m   Correct Option: 6 m
<result>D</result>
Three pieces of timber 36 m, 42 m and 54 m long have to be divided into planks of the same length, What is the greatest possible length of each plank ?