One column of numbers consist of 2842 and 14 when the digits of the numbers are added together the result is 2+8+4+2+ one +4 equals 21 and when the digits of 21 are then added together the end result is 2+1 = 3 if the same process is performed on the numbers in the second column what can be concluded

When a company produces and sells x thousand units per week, its total weekly profit is p thousand dollars, where upper p equals startfraction 800 x over 100 plus x squared endfraction . the production level at t weeks from the present is x equals 4 plus 2 t. find the marginal profit, startfraction dp over dx endfraction and the time rate of change of profit, startfraction dp over dt endfraction . how fast (with respect of time) are profits changing when tequals8?