Elisa swims laps in the pool. When she first started, she completed 10 laps in 25 minutes. Now she can finish 12 laps in 24 minutes. By how many minutes has she improved her lap time?
The choices are...
A) 1/2 minutes
B)3/4 minutes
C)1 minute
D)2 minutes
E)3 minutes
2007-02-24 03:12:26 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
its A. if you divide 10, by 25 you get 2.5
and if you divide 12 by 24 you get .5 thats half a minute dear.
2007-02-24 03:18:14 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Initially, Elisa took 2.5 minutes to finish a lap. Later, it took her only 2 minutes to do it. She has improved by 1/2 minute.
Case 1: 25 min divided by 10 laps = 2.5 min/lap
Case 2: 24 min divided by 12 laps = 2.0 min/lap
Good luck.
2007-02-24 11:20:13 · answer #2 · answered by Ley 2 · 0⤊ 0⤋
One lap now takes her 24/12 which is two minutes.
Before, one lap took her 25/10 which is 2.5 minutes.
So she improved her lap time by half a minutes.
2007-02-24 11:24:13 · answer #3 · answered by CooK 2 · 0⤊ 0⤋
applications of rate is what you need.
first:
25 minutes are 10 laps
giving 10/25 = 2/5
while,
second:
24 minutes are 12 laps
giving 12/24 = 0.5 or ½
since 2/5 is less 1/2
the larger number is the better value of gaining her laps.
so, it is 0.5 or A: ½ minute is the answer!
2007-02-24 11:55:04 · answer #4 · answered by edison c d 4 · 0⤊ 0⤋
A is the answer!!
2007-02-24 11:22:29 · answer #5 · answered by Database 2 · 0⤊ 0⤋