righthand wrote:
Tonya has a contract to plant saplings along the median of a highway. Prior to starting the work, she estimated that she would need 40 saplings to complete the contracted work and that it would take an average of 10 minutes to plant each sapling. Was the amount of time that it took her to complete the work no more than 95 percent of her estimated total time?
(1) The number of saplings that Tonya planted was 2 less than her estimate.
(2) The average time that Tonya spent to plant each sapling was within 15 seconds of her estimated time per sapling.
So for each sapling 600 seconds are required.
Total time taken is 40*600 =24000 sec.
95% of 24000= 22,800 sec.
We need to know whether Tanya's time was within 22,800 sec. or not.
(1) The number of saplings that Tonya planted was 2 less than her estimate.
We do not know the time she took for each sapling, hence cannot figure out her total time. INSUFF.
(2) The average time that Tonya spent to plant each sapling was within 15 seconds of her estimated time per sapling.
We do not know the number of saplings she planted hence here also we cannot figure out her total time.
1+2
Number of saplings 38 and time within 15 sec. of her original time, hence
If she takes 14 seconds extra or 614 seconds for each sapling her total time = 614*38 =23,332, which is more than 95%
If she takes 14 seconds less or 586 seconds for each sapling her total time = 586*38=22,268, which is less than 95%
INSUFF.
Ans- E
Hope it's clear.