Question

f 2/3−3/7=15/63, then the value of =?

Answer 1

Answer:

Add successive powers of 2 to the number:

1+2=3; 3+4=7; 7+8=15; 15+16=31; 31+32=63; 63+64=127.

Or, if we call the first value a1 , the sequence is given by an=2n−1

The first approach to analyzing almost any sequence is to look at the differences of successive elements. In this sequence, that’s 2, 4, 8, 16, 32. That makes the answers above pretty easy.