# Category Archives: Class 11

Question 1. Calculate the mean deviation from the median of the following frequency distribution: Heights in inches 58 59 60 61 62 63 64 65 66… Read More
Question 1. Compute the mean deviation from the median of the following distribution: Class 0-10 10-20 20-30 30-40 40-50 Frequency 5 10 20 5 10… Read More
Question 1. Calculate the mean deviation about the median of the following observation : (i) 3011, 2780, 3020, 2354, 3541, 4150, 5000 (ii) 38, 70,… Read More
In each of the Exercises 1 to 9, find the coordinates of the foci, the vertices, the length of the major axis, the minor axis,… Read More
Question 11. If 28C2r : 24C2r-4=225:11, find r. Solution: (28!/(28-2r)!2r!)/(24!/(24-2r+4)!(2r-4)!)=225/11 28x27x26x25/2r(2r-1)(2r-2)(2r-3)=225/11 28x27x26x25x11=225x(2r)(2r-1)(2r-2)(2r-3) 28x3x26x11=2r(2r-1)(2r-2)(2r-3) 14x2x3x13x2x11=2r(2r-1)(2r-2)(2r-3) 14x13x12x11=2r(2r-1)(2r-2)(2r-3) 2r=14 r=7 Question 12. If nC4,nC5 and nC6 are in… Read More
Solve the inequalities in Exercises 1 to 6. Question 1. 2 ≤ 3x – 4 ≤ 5  Solution: In this case, we have two inequalities,… Read More
Question 8. Find sets A, B and C, such that A ∩ B and B ∩ C and A ∩ C are non-empty sets, and… Read More
Question 1. Find the smallest set A such that A ∪ {1, 2} = {1, 2, 3, 5, 9}. Solution: A ∪ {1, 2} =… Read More
Question 9. Write down all subsets of the following subsets:  (i) {a} (ii) {0,1} (iii){a,b,c} (iv){1,{1}} (v) {ϕ} Solution: We know, if A is a… Read More
Question 1. Which of the following statements are true? Give a reason to support your answer. (i) For any two sets A and B either… Read More
Find the mean deviation about the mean for the data in questions 1 and 2.  Question 1.  4, 7, 8, 9, 10, 12, 13, 17… Read More
Question 1. If A and B are two sets such that A ⊂ B, then Find: (i) A ⋂ B (ii) A ⋃ B Solution:… Read More
Question 15.  There are three copies each of 4 different books. In how many ways can they be arranged in a shelf? Solution:    Total… Read More
Question 1. Find the number of words formed by permuting all the letters of the following words : (i) INDEPENDENCE (ii) INTERMEDIATE (iii) ARRANGE (iv)… Read More
Question 33. How many four digit natural numbers not exceeding 4321 can be formed with the digits 1,2,3,4, if the digits can repeat? Solution: Total… Read More