Twenty one times of a positive number is less than its square by 100. The value of the positive number is
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 25
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Understanding |
Application |
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Suppose the given number is ‘A’ |
So we have: A2 – 21A = 100 A2 – 21A – 100 = 0 A2 – 25A + 4A – 100 = 0 A(A – 25) + 4(A – 25) = 0 (A – 25) (A + 4) = 0 A = 25 A = -4 (Not Possible as the number is positive) Hence, Number = 25 |