Solution - Solve the puzzle if you are genius

This is the solution of the puzzle asked in Previous article Question

Very simple
Since,

6+6+6+6 =  twenty fouR       So R


7+7+7+7 = twenty eighT      So last word R


 .....


8+8+8+8 = thirty twO  So last word O


Thus

9+9+9+9 =  thirty siX

So X is the answer .