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6 Cards in this Set
- Front
- Back
When sum and difference of two numbers (X and Y) are given, then |
X = (sum + difference)/2 Y = (sum + difference)/2 |
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Difference between two digits of two digit number is = |
(Difference in original and interchanged number)/9 |
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Sum of first n odd numbers is |
n*2 |
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Sum of first n even numbers is |
n(n+1) |
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Sum of squares of first n natural numbers is |
n(n+1)(2n+1)/6 |
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Sum of cubes of first n natural numbers is |
[n(n+1)/2]*2 |