the probability that a surgery will succeed equals P and it's bigger than the probability that the surgery will not succeed.

It's known that if 4 surgeries are being done the probability that exactly 2 of them will succeed is 27/128.

Find P.

here is the equation I got:

$\displaystyle 6p^4-12P^3+6P^2-27/128$

FINAL EQUATION:

$\displaystyle 6P^2-12P+5/101/128=0$

FINAL RESULT IS 3\4

can anyone please help me correcting this equation ? I could get the required answer.

i have to do it according to bernouli's principle.