P= 16 over 3 this is the straight forward answer
" 100% " means "the whole thing",
and "is" can be replaced by "is equal to".
You have said "The whole thing of a number is equal to 61."
or
"61 is equal to the whole thing of a number."
The only number that 61 can be equal to is 61.
This does not look easy to factor, so I'd suggest using the quadratic formula:
-1 plus or minus sqrt( 1-4(3)(-5) )
x = -----------------------------------------------
2*3
-1 plus or minus sqrt(61)
= ------------------------------------
6
Thus, there are 2 real, unequal, irrational roots / solutions.