Asked in PPSC, FPSC and other one-paper exams (compiled from unofficial resources).
AlgebraQuadratic Equations
A positive number when decreased by 4 is equal to 21 times the reciprocal of the number. The number is?
- A.$3$
- B.$5$
- C.$7$Correct answer
- D.$9$
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Practice these MCQs in the appQuick fact: Let the number be $x$; then $x - 4 = \frac{21}{x}$ gives $x^2 - 4x - 21 = 0$, so $x = 7$ (positive root). The number is $7$.