Question

A strabismus surgery has a probability of 0.9 of success in the first attempt and a probability of 0.98 of success in the second attempt. Use the techniques of tree diagrams to find the probability the probability that the surgery will be successful within two attempts. (round four digits after the decimal)

Answer 1

i don't need the tree diagram, just the answer
i think the answer must be greater than 0.98 right?

Answer 2

The tree diagram shows the probabilities of the three possible outcomes. You need to add the two values of probability of success.

Answer 3

yes that is what i got but the answer choises are
0.098
0.900
0.002
0.100
0.98
0.02

Answer 4

i think
0.98
is the greater

Answer 5

Perhaps "successful within two attempts" means 'successful after one attempt' if "within" is considered to mean 'fewer than two'. In that case 0.900 would be correct.

Answer 6

then 1 attemp

Answer 7

Correct.

Answer 8

thanks so much