Solution:

98

2+3=2*[3+(2-1)]=8
3+7=3*[7+(3-1)]=27
4+5=4*[5+(4-1)]=32
5+8=5*[8+(5-1)]=60
6+7=6*[7+(6-1)]=72
therefore
7+8=7*[8+(7-1)]=98
x+y=x[y+(x-1)]=x^2+xy-x

Solution:

888 + 88 + 8 + 8 + 8 = 1000

Solution:

Rupees 1000

Solution:

12,345,678,987,654,321

(its amazing and awesome)

Solution:

42857

Let the number be x
10x +1 = 3(100,000 + x)
=> x = 42857.

Solution:

68782
+ 68782
+ 650
========
138214

Solution:

47 + 53 + 59 + 61 = 220

Solution:

58725
58725
3958725
=======
4076175

Solution:

7 * ((3 / 7) + 3) = 24

Solution:

20 + 20 + 20

55 + 5