Melody

Easier way:

90*4=360

81.5*5=407.5

lowest possible for test 4 = 407.5-360=47.5

But lowest possible integer result is 48

Any more reduction - any takers ?      LOL

Tom took five math tests and got an integer score on each of them. He never scored higher than 90, and his lowest score was the fourth test. If his average score, rounded to the nearest integer, was 82, what is the lowest possible score he could have gotten on the fourth test?

The average could have been between 81.5 and 82.5

Say he scored 90 on all the other tests that is a total of 360 for the four other tests

so

$$\\81.5\le \frac{360+fourth}{5}<82.5\\\\
407.5\le 360+fourth<412.5\\\\
47.5\le fourth<52.5\\\\
$But all the scores were integers so$\\\\
$the lowest possible score for the fourth test was $ 48$$

@@ End of Day Wrap  Wed 1/7/15   Sydney, Australia Time   6:00pm  ♪ ♫

Hi all,

Our great answers today were provided by CPhill, Fiora, Zacismyname, TitaniumRome, Sir-Emo-Chappington, Rosala, KidDanger and Alan.  Thank you  

This quadrilateral is a parallelogram and two of the sides are parallel to the x axis.  

That is why it was so easy for CPhill to determine the area :)

Good thinking Radix  

Complementary angles add to 90

and

Supplementary angles add to 180.                  (just like Chris said)

If you can remember the 2 words it is easy to know which is which because 

2 C's make an S     (one reflected and sitting on top of the other one)          and 2*90=180

Thanks Awsomeee