Bunuel wrote:
Rebecca runs at a constant rate on the treadmill and it takes her 2 hours longer to reach a certain milestone than the time it takes Jeff to reach that same milestone. If Jeff also moves at a constant rate and the two are allowed to combine their distances traveled to reach 25% beyond the initial milestone in 3 hours, how many hours would it take for Rebecca alone to reach the equivalent distance of 2 milestones?
(A) 4
(B) 6
(C) 8
(D) 10
(E) 12
Are You Up For the Challenge: 700 Level Questions The first method would be to make use of choices..The choices give us time of R to cover 2 milestone, so half of each choice will give us time taken by R to cover 1 milestone, and THAT half -2 will give us time taken by J..(A) 4
So R takes 4/2 or 2 hrs and J takes 2-2 =0...NOT possible
(B) 6
So R takes 6/2 or 3 hrs and J takes 3-2 =1, so J alone will cover 3/3 or 3 milestones in 3 hrs, but we are looking a combined distance of 1.25 milestone in 3 hrs...NOT possible
(C) 8
So R takes 8/2 or 4 hrs and J takes 4-2 =2, so J alone will cover 3/2 or 1.5 milestones in 3 hrs, but we are looking a combined distance of 1.25 milestone in 3 hrs...NOT possible
(D) 10
So R takes 10/2 or 5 hrs and J takes 5-2 =3, so J alone will cover 1 milestones in 3 hrs and R will cover 3/5 or 0.6 milestones. Combined they cover 1.6, but we are looking a combined distance of 1.25 milestone in 3 hrs...NOT possible
(E) 12
Only choice left, so our answer, but let us check
So R takes 12/2 or 6 hrs and J takes 6-2 =4, so J alone will cover 3/4 or 0.75 milestones in 3 hrs and R will cover 3/6 or 0.5 milestones in 3 hrs. Combined they cover 0.75+0.5=1.25 milestones..... Our answer
E