A family has 2 children. Find the probability that both are boys, if it is known that: (i) at least one of the children is a boy,            (ii) the elder child is a boy.

Four persons are to be chosen at random from a group of 3 men, 2 women and 4 children. Find the probability of selecting: (i)1man  1woman and 2 children (ii)Exactly 2 children             (iii) 2 women

The number of solutions of z^2+bar z=0 is (a) 1           (b) 2 (c) 3           (d) 4

Draw rough diagrams to illustrate the following: (i) Open curve         (ii) Closed curve

The number of integral pairs (x,y) satisfying the equation (x-y)^2+2y^2=27 is: a.    8 b.    7 c.    6 d.    5

How many diagonals does each of the following have? (i)A convex quadrilateral (ii)A regular hexagon             (iii)   A triangle

In an AP, S_p=q , S_q=p . Then S_(p+q) is equal to: a.     0 b.     -(p+q) c.     (p+q) d.     pq

Find the volume in cubic decimetre of each of the cubes whose side is (i)1.5m          (ii)  75cm        (iii)  2dm 5cm

Following are some figures: Classify each of these figures on the basis of the following:(i) Simple curve                (ii)    Simple closed curve (iii) Polygon                         (iv)  Convex polygon (v)Concave polygon          (vi)   Not a curve   Figures

A box contains 3 blue, 2 white, and 4 red marbles. If a marble is drawn at random from the box, what is the probability that it will be(i) white?         (ii) blue?          (iii) red?

The mean and standard deviation of marks obtained by 50 students of a class in three subject, Mathematics, Physics and Chemistry are given below: Subject      Mathematics         Physics                Chemistry                           Mean            42                             32                          40.9 Standard       12                            15                          20 Deviation Which of the three subjects shows the highest variability in marks and which shows the lowest?