16Hit1600
Advanced MathVery hardNumber from the sum with its reciprocal

Advanced Math practice question

The sum of a positive number and its reciprocal is 10/3. If the number is greater than 1, what is the number?

Answer: 3

x + 1/x = 10/3 gives 3x² − 10x + 3 = (3x − 1)(x − 3) = 0, so x = 3 or 1/3; the one greater than 1 is 3.

Common wrong answers

If you answered 2
2 gives 2 + 1/2 = 2.5.
If you answered 1/3
1/3 is the other solution, which is less than 1.
If you answered 10/3
10/3 is the given sum.

More Advanced Math questions

Not affiliated with the College Board. SAT is a trademark of the College Board.