What is the missing probability P(X=7)? Your answer should include the second decimal place.

X = # information | probability:

1 | 0.0

2 | 0.02

3 | 0.04

4 | 0.07

5 | 0.15

6 | 0.18

7 | ?

8 | 0.14

9 | 0.11

10 | 0.05

I calculate the probability of 7 as 0.24 (1- sum of all other probabilities)

however I always get the below question wrong;

Given that the person recalls at least 7 pieces of information, what is the probability that they recall all 10 pieces? Please round to the second decimal place.

My logic is: P(A and B) = P(A) = P(10) = 0.05

and P(A|B) = 0.05/ P(B), 0.24 = 0.208 ~0.21

Can you help me understand what I am doing wrong, it is driving me crazy..

Thank you for your help