Question
What is the value of 1² + 3² + 5² + 7² + 9²
................ 19²?Solution
Sum of the squares of odd number = (n(n+1)(n+2))/6 Where n = Last term = (19×20×21)/6 = 1330 type-2 Sum of the squares of odd number = (n(2n+1) (2n-1))/3 Where n = (Last term+1)/2= (19+1)/2=10 = (10×21×19)/3 = 1330
12, 24, 72, 288, 1440, ?
120     119     ?     352      2464     2455
...12 3 15 ? 153 756
...70    191    47    216    ?    245
105   107   111   114   ?   127
19.11 × 5.98 + 20.03 × 3.12 – 34.95 + 97.9 × 3.02 =?
75    196    52    221    ?    250
5Â Â Â Â Â Â Â Â Â 18Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 44Â Â Â Â Â Â Â Â Â Â Â 83Â Â Â Â Â Â Â Â Â 135Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 200Â Â Â Â ...
3, 4, 10, 33, 136, ?, 4116
If 2.5 3.5 x 30 124 625
Then, x ² - 1 - 2x = ?
...
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