can someone explain this step by step please? Thank you!

Consider the following limit order book for FinTrade stock. The last trade in the stock occurred at a price of $$50.$

a$.$ If a market sell order for $150$ shares comes in$,$ will it be filled immediately? At what price will it be filled? If not, please describe the situation and explain why. $($Round your answer to $2$ decimal places.$)$

b$.$ If a limit sell order for $150$ shares at the price of $49\mathrm{.}78$ comes in$,$ will it be filled immediately? At what price will it be filled? If not, please describe the situation and explain why. $($Round your answer to $2$ decimal places.$)$

c$.$ Based on the current order book structure, Bill expects the stock price will go down. Is it a reasonable expectation? Explain why.

d$.$ Suppose a moderate volume of market buy order or a market sell order having the same size comes in$,$ which one do you think will cause a larger stock price change? Explain why.