Is this equation true or false -30 . 10 =300

Aparallel system functions whenever at least one of its components works. consider a parallel system of n components, and suppose each component works independently with probability 0.5. find the conditional probability that component n works given that the system is working

Jonah runs 3/5 miles on sunday and 7/10 mile on monday. he uses the model to find that he can ran a total of 1 mile . what mistake does jonah make

Which one ? is the answer and how to find this answer