least distance problem-GMAT PREP

one possible way to solve is to find LCM of 7 and 5, it must be 35
and then list all multiples of 5 and 7 between 1 and 35
for 5 it must be 5. 10. 15. 20. 25.30.35
for 7 1, 14, 21, 28, 35
the least distance 21-20=1. or 15-14=1
so desired answer 1/35

clock60 wrote:one possible way to solve is to find LCM of 7 and 5, it must be 35
and then list all multiples of 5 and 7 between 1 and 35
for 5 it must be 5. 10. 15. 20. 25.30.35
for 7 1, 14, 21, 28, 35
the least distance 21-20=1. or 15-14=1
so desired answer 1/35

Thanks, for maximum distance (35-1)/35 ?? correct ?

Large tick marks are divided into fifths:1/5,2/5,3/5,4/5,5/5

Small tick marks are divided into sevenths:1/7,2/7,3/7,4/7,5/7,6/7,7/7

LCM(5,7)=35 and have a common denominator on both terms.

-->Large tick marks:7/35,14/35,21/35,28/35,35/35

-->Small tick marks:5/35,10/35,15/35,20/35,25/35,30/35,35/35


Least distance =21/35-20/35=1/35

i am not too sure but largest possible distance 1-0=1, or 35-0=35/35=1
as you need largest possible value between any of two ticks

Largest possible distance=35/35-5/35=30/35