Asurvey of 398 children given at a local elementary school showed that 200 like chocolate ice cream 125 like pistachio ice cream, and 148 do not like chocolate or pistachio ice cream. how many children like at most one kind of ice cream mentioned in the survey?

1 number

if we use a graphing calculator, there is only one such number that satisfies the conclusion of the mean value theorem, that is, a number such that

where the right-hand side is the average rate of change of f on the interval [0.5,0.75], which is the slope of the secant line.

in the attached graph, the black line is the secant line which has its slope as the average rate of change of f on [0.5,0.75], while the orange line is the only tangent line to the graph of f in the interval that satisfies the mvt conclusion.