Stephanie, Regine, and Brian ran a 20 mile race. Stephanie and Regine'

Hi kostyan5,

Can you please clarify how you have assumed S and R to be 2.5 because even B can also be 2.5 right?
if in that case anyone i.e S or R or B can win the race,please clarify on the same

I think the answer is E as we do not exactly know who is slower than the other two.

Given that S+R=B+2, where S, R, and B are times in which Stephanie, Regine, and Brian completed the race.

Min time one could complete the race is 20/8=2.5 hours. Let's see if Brian could have won the race: if he ran at the fastest rate, he would complete the race in 2.5 hours, so combined time needed for Stephanie and Regine would be S+R=B+2=4.5 hours, which is not possible as sum of two must be more than or equal the twice the least time: 2*2.5=5. So Brian could not have won the race.

There is no reason to distinguish Stephanie and Regine so if one could have won the race, another also could. So both could have won the race.

Answer: D.

To elaborate more: the least time one could complete the race is 20/8=2.5 hours, hence \(S+R\geq{5}\). Let's see if Brian could have won the race: best chances to win he would have if he ran at the fastest rate, so he would complete the race in 2.5 hours, so combined time needed for Stephanie and Regine would be S+R=B+2=4.5 hours, but we know that \(S+B\geq{5}\), so even if Brian ran at his fastest rate to win the race, given equation S+R=B+2 can not hold true. Hence Brian could not have won the race.

Hope it's clear.

OPEN DISCUSSION OF THIS QUESTION IS HERE: stephanie-regine-and-brian-ran-a-20-mile-race-stephanie-127050.html