Can You Pass This Test?

A student can pass test 1 with a probability of 3/4 . For the next three tests, the probability of passing in test k(k ge 2) depends on his passing test (k-1). If he passes test (k 1), then probability of passing test k is 3/4 otherwise 1/4 . Let p be the probability that he passes at least three tests out of first four, then 16/27p is equal to ____

At the university entrance exam, a candidate is admitted according to whether he has passed or failed the test. Of the candidates who are really capable, 80 % pass the test and of the incapable, 30 % pass the test. Given that 40 % of the candidates are really capable, then the proportion of the really capable students who can pass the test to the total students who can pass is about ?

What is a base ? Name any two bases. How can you test the presence of a base in a substance?

What is an acid ? Name any two acids. How can you test the presence of an acid in a substance?