A straight pipe 1 meter in length was marked off in fourths and also in fifths. If the pipe was then cut into separate pieces at each of these markings, which of the following gives all the different lengths of the pieces, in fractions of a meter? Pick.
A) 1/20 and 1/10 only
B) 1/5, 1/20 ,3/20 and 1/10
C) 1/6, 1/4, and 1/3
D) 1/12, 1/6 and 1/4
E) 1/12, 1/6, and 1/3
Generally fast way to solve such problem is writing the different marks in ascending/descending order with same denominator:   Here 4th : 0/4, 1/4, 2/4, 3/4, 4/4   and 5th : 0/5, 1/5, 2/5, 3/5 , 4/5, 5/5   Now with understood common denominator 20 write the numbers : for 4th : 0,5,10,15,20 and for 5th : 0,4,8,12,16,20   Now comine : 0,4,5,8,10,12,15,16,20   Now find the cut with denominator 20 (Substracrt adjacent terms : 1/5, 1/20, 3/20, 1/10,1/10,3/20,1/20,1/5 i.e. 1/5, 1/20 ,3/20 and 1/10 after removing duplicates.   Answer : 1/5, 1/20 ,3/20 and 1/10
<result>B</result>
A straight pipe 1 meter in length was marked off in fourths and also in fifths. If the pipe was then cut into separate pieces at each of these markings, which of the following gives all the different lengths of the pieces, in fractions of a meter?