NUMBER

Which of the following are true for an element ? (i) Atomic number = number of protons + number of electrons (ii) Mass number = number of protons + number of neutrons (iii) Atomic number = number of protons = number of neutrons (iv) Atomic number = number of protons = number of electrons

Contrapositive of the statement. If the squares of two numbers are equal then the numbers are equal is (A) If the squares of two numbers are equal then the numbers are equal (B) If the squares of two numbers are not equal then the numbers are not equal (C) If two numbers are not equal then the square of the numbers are not equal (D) If squares of two numbers are equal then the numbers are to equal

There are five numbers. The second number is 25% more than the first or third number, the fourth number is 5/4 of the third number and the fifth number is 3/2 of the third number. What is the average of the five numbers if the first number is 40?

Consider the following statements : 1. There is a finite a number of rational numbers between any two rational numbers. 2. There is an infinite number of rational numbers between any two rational numbers. 3. There is a finite number of irrational numbers between any two rational numbers. Which of the above statements is/are correct?

The number of boys in a classroom is 6 less than the double of the number of girls in the classroom.If the total number of students in the class is 30 then find the number of boys and the number of girls.

There are 45 persons working in an office.If the number of females is 25 and the remaining are males,find the ratio of : (a) The number of females to number of males.(b) The number of males to number of females.