Rosie the road-runner recently ran in two road races. The second race was 20% further in distance than the..?

Question

Rosie the road-runner recently ran in two road races. The second race was 20% further in distance than the first race and Rosie's average speed was 20% slower in the second race. By what percentage was her time for the second race greater than that for the first?

A- 33.5%
B- 40%
C- 44%
D- 50%
E- 66&2/3%

The person to give me the best answer along with a valid reason to back it up, will get 10 points.

Answer 1

Example of solution

Race 1 - run 10 miles at 10 mph
Race 2 - run 12 miles at 8 mph

12 miles is 20% further than 10 miles and 8mph is 20% slower than 10 mph

Race 1 would take 1 hour and race 2 would take 1.5 hours.

The Key to the question is "by what percentage is the second race GREATER than the first," the question is not the first race is what percentage of the second race.

1.5 hours is 50% greater than 1 hour because

1.5 hours - 1 hour = .5 hours and .5 is 50% of 1, so therefore the time for race 2 (1.5 hours) is greater than race 1 ( 1 hour) by 50%.

No matter how you change the numbers the second race will always take 50% longer than the first race.

The answer is D - 50%

Answer 2

Road Runner

Answer 3

The answer would be E. - 66.66666666667%.

The reason for this is as below:

The first race could be100km ran at 100kph.
The second would then be 120km ran at 80 kph.

The first race would be run at an average speed of 1km per minute, where the second race would be run at an average of 1.5km per minute.

You then divide the 1km per minute speed by the 1.5km per minute speed and then multiply that answer by 100 to get the percentage difference which equals 66.6666666667 or 66 & 2/3%. Hope this helps.

Answer 4

B-40%

Answer 5

if race 1 100m in 100 secs speed is 1m/sec

race 2 will be120 m run at speed of 1.2m/sec will take 144 secs

time increased by 44%

Answer 6

Or, algebra:

time 1= T1
time2=T2

distance 1=D1
distance 2=D2

Speed 1=S1
Speed 2=S2

D2=D1+.20(D1)
D2=1.20(D1)

S2=S1-.20(S1)
S2=.80(S1)

T1=D1/S1

T2=1.2(D1) / .8(S1)

T2=1.5(D1/S1)

T2=1.5(T1)

PERCENTAGE DIFFERENCE

1.5(T1)-1(T1)=.5(T1) OR 50% DIFFERENCE GREATER


The one speed IS 66 2/3 of the other speed, but the question asks for the percentage DIFFERENCE IN TIME!

1.5 is 50% more than 1: D is the answer

You have to read these word problems carefully!!!

Answer 7

Did Wile E Coyote catch this road runner?

Answer 8

glad i dont go to school anymore

Answer 9

k
none of the above!