Tricks Flashcards
1
Q
ODD + EVEN
A
ODD
2
Q
ODD * EVEN
A
EVEN
3
Q
ODD + ODD
A
EVEN
4
Q
EVEN + EVEN
A
EVEN
5
Q
ODD * ODD
A
ODD
6
Q
EVEN * EVEN
A
EVEN
7
Q
0.aaaaa…
A
a/9
8
Q
0.abcabc…
A
abc/999
9
Q
0.abcbcbc…
A
0+abc-a/990
10
Q
Summation of odd numbers starting from1
A
1+3+5+7+…+2n-1=n^2
11
Q
Summation of even numbers
A
2+4+6+…+2n=n+n^2
12
Q
1+2+3+4+…+n
A
n(n+1)/2
13
Q
1^2+2^2+3^2+…
A
n(n+1)(2n+1)/6
14
Q
1^3+2^3+3^3+….
A
[n(n+1)/2]^2
15
Q
A
