AS Level stats help!!

(a) The discrete random variable X ~ B(40, 0.27) Find P(X ≥ 16)Past Past records suggest that 30% of customers who buy baked beans from a large supermarket buy them in single tins. A new manager suspects that there has been a change in the proportion of customers who buy baked beans in single tins. A random sample of 20 customers who had bought baked beans was taken.B) Write down the hypotheses that should be used to test the manager's suspicion.(c) Using a 10% level of significance, find the critical region for a two-tailed test to answer the manager's suspicion. You should state the probability of rejection in each tail, which should be less than 0.05I’m really struggling with understanding what to do for C, the mark scheme is so useless

It would probably help to post the mark scheme and be clear about what you understand / dont understand. It sounds like a fairly typical sample mean hypothesis test.

Edit is it Q4 in
https://pmt.physicsandmathstutor.com/download/Maths/A-level/S2/Papers-Edexcel-Tiered/10%20Gold%202%20-%20S2%20Edexcel.pdf

Yes it is that one! I can’t upload an image because it keeps saying image error sorry ):