   # You take a test, and 60% pass the first time and 40% fail. The second time around,80% pass the test and 20% fail.

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You take a test, and 60% pass the first time and 40% fail. The second time around,80% pass the test and 20% fail. The third time, 90% pass and 10% fail.

a) What is the probability that you pass on the 2nd time?
b) What is the probability that you pass on the 3rd time?
c) What is the probability you fail? posted Aug 13, 2015

1:)) prob of pass second time == fail1st time * pass 2nd time ==== .4 * .8 === .32

2:)) prob of pass third time == fail1st time * fail 2nd time * pass 3rd time ==== .4 * .2 * .9=== .072

3:)) prob of fail == fail1st time * fail 2nd time * fail 3rd time ==== .4 * .2 * .1===.008 answer Sep 28, 2015

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+1 vote

You take a test, and 60% pass the first time and 40% fail. The second time around,80% pass the test and 20% fail.

What is the probability that you pass on the 2nd time?