As per the given series ( 9, 19, 39, 79 .. ?)
next_number = (number + 10 * (1, 2, 4, 8, ..)), i.e
9 + (10 * 1) = 19 19 + (10 * 2) = 39 39 + (10 * 4) = 79 79 + (10 * 8) = 159
One more solution is: next_number = (number * 2) + 1
9 * 2 + 1 = 18 + 1 ==> 19 19 * 2 + 1 = 38 + 1 ==> 39 39 * 2 + 1 = 78 + 1 ==> 79 79 * 2 + 1 = 158 + 1 ==> 159
answer is 159
159 9x2+1=19,19x2+1=39,39x2+1-79,79x2+1=159
(9*2) + 1 = 19 (19*2) + 1 = 39 (39*2) + 1 = 79 (79*2) + 1 = 159
So answer is 159
10 added to 9, to get 19. Double of 10, 20 added to 19 to get 39. Double of 20, 40 added to 39 to get 79. Double of 40, 80 added to 79 to get 159.
What is the next number in the sequence - 1, 7, 10, 13, 19, 23, 28, 31, 32, 44, 49, 68, 70, 79, 82, 86, 91, 94, 97, 100, 103, 109, 129, 130, ?