Maths Doubt

Posted by Granpa Simpson on May 06, 2014; 10:24pm
URL: http://discussion-forum.276.s1.nabble.com/Maths-Doubt-tp7588767.html

The number of sequences of length five with 0 and 1 as terms which contains atleast 2 consecutive zeroes is..??....I am getting 20 as the answer but the answer is 19..plz help..thanx in advance...!!!!