On every birthday of my life, my mother has seen to it that my cake contains my age in candles. Starting on my fourth birthday, I have always blown out all my candles. Before that age, I averaged a 50% total blowout rate. So far, I have blown out exactly 900 candles. How old am I
Options:
A . 43
B . 42
C . 44
D . 45
Answer: Option B : B n(n+1)2−1+2+32=900:n(n+1)2=903; n(n+1) = 1806, n = 42.
