CA Foundation · Quantitative Aptitude · Equations
If one root of the equation x² − 7x + k = 0 is 3 more than the other root, what is the value of k?
The value of k is 10. With roots a and a + 3 summing to 7, the roots are 2 and 5, and their product, which equals k, is 10.
- A10Correct
- B4
- C12
- D−10
Explanation
Let the roots be a and a + 3. Sum: 2a + 3 = 7, so a = 2 and the roots are 2 and 5. Product k = 2 × 5 = 10. Check: 4 − 14 + 10 = 0. The value 12 comes from taking roots 3 and 4, which differ by 1, not 3.
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