Category Archives: School Learning

Question 1. If nC8=nC2, find nC2. Solution:  We know that, nCr=nC(n-r) For the given question, r=8 and n-r=2 Hence, n=r+(n-r)=8+2=10 OR Using formula (1), nC8=nC(n-r) 8(n-8)=2(n-2) … Read More
Question 1: A wooden bookshelf has external dimensions as follows: Height = 110cm, Depth = 25cm, Breadth = 85cm (see fig. 13.31). The thickness of… Read More
Question 1: Given A = {1, 2, 3}, B = {3, 4}, C = {4, 5, 6}, find (A × B) ∩ (B × C).… Read More
Chapter 12 Percentage – Exercise 12.2 | Set 1 Question 14. An alloy of tin and copper consists of 15 parts of tin and 105… Read More
Question 1. Find:(i) 22% of 120(ii) 25% of Rs 1000(iii) 25% of 10 kg(iv) 16.5% of 5000 meter(v) 135% of 80 cm(vi) 2.5% of 10000… Read More
Question 1. Which of the following are examples of empty set? (i) Set of all even natural numbers divisible by 5. (ii) Set of all… Read More
Question 1. Find the square root of : (i) 441/961 (ii) 324/841 (iii) 4 29⁄29  (iv) 2 14⁄25  (v) 2 137⁄196     (vi) 23… Read More
Question 1. Find the square root of each of the following correct to three places of decimal. i) 5            … Read More
Question 1. How many balls, each of radius 1 cm, can be made from a solid sphere of lead of radius 8 cm?  Solution: R… Read More
Question 1. The graphs of y = p(x) are given in Fig. 2.10 below, for some polynomials p(x). Find the number of zeroes of p(x),… Read More
Question 1. Prove that √5 is irrational. Solution: Let √5 be a rational number. √5 = p/q be a rational number, where p and q… Read More
Question 1. Write the first five terms of a sequence whose nth term is an=n(n+2). Solution:  Given, an = n(n + 2) Putting value of… Read More
Chapter 6 Linear Inequalities – Exercise 6.1 | Set 1 Question 13. 2 (2x + 3) – 10 < 6 (x – 2) Solution: Given,… Read More
Question 1. Solve 24x < 100, when (i) x is a natural number. (ii) x is an integer. Solution: (i) when x is a natural… Read More
In each of the following Exercises 1 to 6, find the coordinates of the focus, axis of the parabola, the equation of the directrix and… Read More