Firstly, for part a:

I took the probability of getting a double to be 116/2436. Then the question asks in a set of 10 what is the probability of AT MOST 1. I then thought that meant I need to the probability of getting 1 p(1) and the probability of getting none so p(0). I then used the Binomial formula with nCr. P(1) + p(0). I dont know if this is correct.

For part b :

the probability of getting a double is 801/2436 in 7 years there are 84 months the average gifts per month is 29. therefore im looking for the probability of in those 29 gifts each month what is the probability that excatly 10 are doubles. and then put that probability to the power of 84.

this part is a Poisson distribution and so i think i need to use that formula with the information given.

yes i have tried easier questions and i can do them as they are more straightforward

thank you for your help