If four coins are tossed together, what is the probability of at least getting 2 heads?

Find the probability that a two-digit number, chosen at random, is a multiple of 4 given that it is also a multiple of 6.

There are 200 balls (numbered 1 to 200) in a box. Find the probability of choosing a ball which bears either perfect cube or perfect square and the unit digit is either multiple of 3 or multiple of 2?

A bag contains ‘x’ red, ‘2x – 1’ blue and ‘3x – 2’ green balls. Two balls are randomly drawn from the bag and the probability that a blue ball and a green ball are drawn is 1/3. Find the total number of balls in the bag.

A bag contains certain number of green and pink balls. The ratio of the number of green and pink balls in the bag is 2: 3 respectively. Two balls are randomly drawn from the bag and the probability that both the balls are pink is 6/17. Find the total number of balls in the bag.

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