The 20th term of the series a, b , b, c, c, c, d, d, d, d, e, e, e, e, e, .... is
Choose one
A) a B) b C) c D) d E) e
a is one time, b,2 times so on...   so 20=n(n+1)/2..   0r n(n+1)= 40... now 6*7=30... 5*6&lt;40 so n= 6.. and 20th alphabet is e..ans e
<result>E</result>
The 20th term of the series a, b , b, c, c, c, d, d, d, d, e, e, e, e, e, .... is