The answer to squared numbers are as follow :
Firstly, you need to know the formula 1*1 + 2*2 + 3*3 + ......+ x*x = x/6(x+1)(2x+1)
Then, 1*1 + 3*3 + ...... + 99*99 = (1*1 + 2*2 + 3*3 +...... + 100*100 ) - (2*2 + 4*4 + ......
100*100 )
= [ (100/6) (100+1) (2*100+1) ]-[ 2*2 ( 1*1 + 2*2 + 3*3 +......
50*50) ]
= 338350 - [4 * (50/6) (50+1) (2*50+1)
= 338350 - 171700
= 166650
1/x - 1/y = 1/4 . What is the value of
2y + 3xy - 2x / y - x - 2xy
Look out for the solutions. Meanwhile, you are invited to post your own comments via the comments box.
Four married couples, with names John, James, Matthew, Shaun, Lily, Elaine, Laura and Helen attended a function. At the function, they are required to shake hands with each other. The following information is given:
1 James shake hands with Lily.
2 John shake hands with Matthew' s wife
3 Elaine shake hands with Laura's husband
4 Shaun shake hands with John's wife
5 Laura shake hands with Lily's husband
The wife of James is_______
Look out for the solution to this question! Meanwhile, you are welcome to post your solutions via the comments box.
1*1 + 3*3 + 5*5 + 7*7 + 9*9 +...... +99*99
Look out for the solution tommorow.
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