Given below are pairs of statements. Combine them using ‘if and only if' :
p: if Anil is intelligent, then he scores 92%. q : If Anil scores 92%. then he is intelligent.

Given below are pairs of statements. Combine them using ‘if and only if' : p: If two lines are parallel, then their slopes are equal. q: If the slopes of two lines are equal, then they are parallel.

Given below are two pairs of statements. Combine these two statements using if and only if : p: If a rectangle is a square, then all its four sides are equal. q : If all the four sides of a rectangle are equal, then the rectangle is a square.

Given below are two pairs of statements. Combine these two statements using if and only if : p : If the sum of digits of a number is divisible by 3, then the number is divisible by 3. q : If a number is divisible by 3, then the sum of its digits is divisible by 3.

Let p : ‘He is rich’ and q : ‘He is happy’ be the given statements. Write the following statement in the symbolic form, using p and q. If he is rich, then he is unhappy.

Arun bought a pair of skates at a sale where the discount given was 20%. If the amount he pays is Rs 1,600, find the marked price.

Change the following statements using expressions into statements in ordinary language.(For example, given Salim scores r runs in a cricket match, Nalin scores (r+15) runs. In ordinary language – Nalin scores 15 runs more than Salim). A notebook costs p. The book costs 3p.

The scores of 48 children in an intelligence test are shown in the following : Calculate the variance sigma^2 and find out the percentage of children whose scores lie between bar x- sigma and bar x+sigma .

Marks obtained by 2500 students are shown in the following table: A student is selected at random. Find the probability that : he scores more than 80% marks.

Marks obtained by 2500 students are shown in the following table: A student is selected at random. Find the probability that : he scores less than 60% marks.