83, 89, and 97 are three primes between 80 and 100.
The primes between 30 and 50 are 31, 37, 41, 43, and 47, all of which are odd. All other numbers between 30 and 50 are composite.
To mentally find 2*50*25, you could either first multiply 25 by 2, to get 50*50, which can easily be calculated as 2500, or you could multiply the 50 by 2, for a result of 100*25, which is clearly also 2500.
Since 83-59=24, 83 is added by 28 so your answer would be 111.
The law of supply<span> states that the quantity of a good </span>supplied<span> (i.e., the amount owners or producers offer for sale) rises as the market price rises, and falls as the price falls. Conversely, the </span>law<span> of </span>demand<span> (see </span>demand<span>) says that the quantity of a good demanded falls as the price rises, and vice versa.</span>
82% = 82/100
38/50 = 76/100
Average of 76 and 82 = 79
Getting a score of 38 out of 50 will hurt his grade, as it will bring the average down to 79%