In a class of 25 students comprising 15 boys, what is the probability that exactly one of the three class representatives is a girl?

If two dices are rolled, what is the probability that a number greater than 3 comes on at least one dice?

In a bag there are 4 green,”x” red and “x+2” blue pens. If two pens are drawn at random one after the other, the probability that first pen is blue and second pen is red is 5/44. What is the value of x?

If the letters of the word “CONJUNCTION” are arranged in a circle what is the probability that no two vowels are together?

A courier service guy has to deliver a parcel to a particular flat in an apartment. There are five floors in the apartment and a ground floor. There are twelve flats on each floor and ground floor is for parking. The flats are numbered according to the floor, the flats on the first floor are numbered 101,102 ….112, similarly on the second floor, flats are numbered as 201,202…….212, and this is repeated on each floor. The courier guy forgot the number of the flat but remembers that it was not on second or third floor and digit “1” was there exactly once in the flat number. What is the probability that he delivered the courier in the correct flat?

A. \(\frac {1} {16}\)  B. \(\frac {1 } {24}\)  C. \(\frac {1 } {1 4}\)  D.\(\frac {1 } {22 }\)  E. None of these

There are two round tables with seven and five chairs. What is the probability of seating twelve people on these tables such that two particular persons don’t sit on the same table?

A \(\frac {1} {66}\).  B \(\frac {35} {132}\)   C \(\frac {32} {66}\). D \(\frac {25} {66}\). E. None of these

There is a dart board with five concentric circles of radius 4cm, 6cm, 10cm, 14cm and 24cm. What is the probability that a dart thrown will hit the board between smallest and second largest circle? A. \(\frac {9} {19}\)  B. \(\frac {49} {144}\)   C. \(\frac {83} {144}\)  D. \(\frac {5} {16}\)   E. None of these

If three hunters A, B and C can hit targets with probabilities 0.5, 0.4 and 0.1 respectively, what is the probability that hunter C kills a deer after both A and B have fired at it once, assuming that it only takes a hunter one shot to kill the deer? (A hunter hits or misses independent of what the other hunters have done.)

A. 0.03  B. 0.01  C. 0.1  D. 0.02  E. None of these

A bag contains 7 red, 5 green and 6 blue balls. Three balls are drawn one by one at random without replacement. Find the probability that the first ball is red, second ball is green and third ball is blue?

A. \(\frac {31} {512}\)  B \(\frac {35} {816}\). C \(\frac {33} {713}\).  D \(\frac {34} {812}\)  E. None of these

Two dice are thrown simultaneously. Find the probability that sum of the numbers on both the dice is a prime number.

A  \(\frac {1} {4}\). B \(\frac {5} {12}\). C. \(\frac {7} {12}\)  D \(\frac {11} {12}\) E. None of these

A man and his wife appear in an interview. The probability of husband‘s selection is 1/7 and the probability of wife‘s selection is 1/5. What is the probability that only one of them is selected?

A. \(\frac {2} {7}\)  B  \(\frac {1} {25}\). C   \(\frac {1} {3}\).  D  \(\frac {1}{35}\)  E  \(\frac {1} {49}\)