Sort:  

yeah, I figured the pattern between A and B too, but between B and C I didn't. It was hellish counting.

ye sometimes starting with small cases, discover the general formula, and apply it to large cases. can be one of the method to solve a math problem! :)

Coin Marketplace

STEEM 0.16
TRX 0.15
JST 0.028
BTC 58949.08
ETH 2306.78
USDT 1.00
SBD 2.47