Three pieces of timber 42 m, 49 m and 63 m long have to be divided into planks of the same length, What is the greatest possible length of each plank ? Choose the correct choice from the following answers:
A) 7 m
B) 14 m
C) 42 m
D) 63 m
E) None of these
7 mnswer   Greatest possible length of each plank = H.C.F of 42, 49, 63 = 7 m   Correct Option: 7 m
<result>A</result>
Three pieces of timber 42 m, 49 m and 63 m long have to be divided into planks of the same length, What is the greatest possible length of each plank ?