Question #ee05c84e - SAT Suite Question Bank

ID: ee05c84e

Modded SAT Question Bank by Abdullah Mallik

$f of x equals, open parenthesis, x plus 0 point 2 5 x, close parenthesis, times, open parenthesis, 50 minus x, close parenthesis$

The function f is defined above. What is the value of $f of 20$ ?

250
500
750
2,000

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Correct Answer: C

Rationale

Choice C is correct. Adding the like terms x and $0 point 2 5 x$ yields the equation $f of x equals, 1 point 2 5 x times, open parenthesis, 50 minus x, close parenthesis$ . Substituting 20 for x yields $f of 20 equals, open parenthesis, 1 point 2 5 times 20, close parenthesis, times, open parenthesis, 50 minus 20, close parenthesis$ . The product $1 point 2 5 times 20$ is equal to 25, and the difference $50 minus 20$ is equal to 30. Substituting these values in the given equation gives $f of 20 equals, 25 times 30$ , and multiplying 25 by 30 results in $f of 20 equals 750$ .

Choices A, B, and D are incorrect and may result from conceptual or computational errors when finding the value of $f of 20$ .

Question Difficulty: Easy