Hi

i need help with the attached question

I have attempted the question but i am stuck on parts d) to h)

My answers so far are

a) i substituted in hence my answer was 0.112

b) =0.207

c) =0.117

my guess to part d was

=0.4903

Probability of first three not failing is =0.7 hence answer is =0.7

any help is appreichated

thanks