Given a American put option, use a binomial tree with monthly steps h=1/12 that is step length.

Let S(0) =100 (Stock price)

K= 110 (Strike price)

r= 0.03 (Risk free-rate)

T=1 (year)

Volatility= 20%.

a) but the share has a known dividend yield of 5% which will be paid out in 0.6 years. Calculate the price of the option by making a binomial tree with monthly steps?

I really need help with this, can someone help me? what is the formula for known dividend yield?

Thank you