AIEEE Exam

If a number is chosen at random from the set {1,2,3,.....,28,29,30}.What is the probability that
the number chosen is a product of exactly two different prime numbers?

Read Solution (Total 2)

Here, S = {1, 2, 3, 4, ...., 29, 30} = n(S) = 30

Let E = event of chosen a number which product is exactly two different prime numbers = {6, 10, 14, 15, 21, 22, 26} = n(E) = 7

p(E) = n(E)/ n(S) = 7/30
12 years agoHelpfull: Yes(5) No(0)

probability that the number chosen is a product of exactly two different prime number = 7/30.
This is because only the numbers 6,10,14,15,21,22,26 are products of exactly two different prime number as 2*3,2*5,2*7,3*5,3*7,2*11,2*13.
12 years agoHelpfull: Yes(2) No(0)

AIEEE Other Question

There are two poles, one each on either bank of a river, just opposite to each other. One pole is 60 m high. From the top of this pole, the angles of depression of the top and the foot of the other pole are 30� and 60� respectively. Find the width of the river and the height of the other pole. A person is count 4500 notes(currency)
.If An denoted the no.of note he count in (n)min and if a1=a2=a3....a10=150 and a10,a11,a12............... are in A.P with common difference =-2. Find the time taken by him to count all the notes.