10th Maths - Book Back Answers - Chapter 8 Unit - Excercise 8.5 - English Medium Guides

 

SSLC / 10th - Maths - Book Back Answers - Chapter 8 Unit Excercise 8.5 - English Medium

Tamil Nadu Board 10th Standard Maths - Chapter 8 Unit Exercise 8.5: Book Back Answers and Solutions

    This post covers the book back answers and solutions for Chapter 8 Unit Exercise 8.5 – Maths from the Tamil Nadu State Board 10th Standard textbook. These detailed answers have been carefully prepared by our expert teachers at KalviTips.com.

    We have explained each answer in a simple, easy-to-understand format, highlighting important points step by step under the relevant subtopics. Students are advised to read and memorize these subtopics thoroughly. Once you understand the main concepts, you’ll be able to connect other related points with real-life examples and confidently present them in your tests and exams.

    By going through this material, you’ll gain a strong understanding of Chapter 8 Unit Exercise 8.5 along with the corresponding book back questions and answers (PDF format).

Question Types Covered:

• 1 Mark Questions: Choose the correct answer, Fill in the blanks, Identify the correct statement, Match the following 
• 2 Mark Questions: Answer briefly 
• 3, 4, and 5 Mark Questions: Answer in detail

All answers are presented in a clear and student-friendly manner, focusing on key points to help you score full marks.

All the best, Class 10 students! Prepare well and aim for top scores. Thank you!

Chapter 8 Statistics and Probability Unit Ex 8.5

1. Which of the following is not a measure of dispersion?
(A) Range
(B) Standard deviation
(C) Arithmetic mean
(D) Variance
Answer Key:

(C) Arithmetic mean

 
2. The range of the data 8, 8, 8, 8, 8. . . 8 is
(A) 0
(B) 1
(C) 8
(D) 3
Answer Key:
(A) 0  

3. The sum of all deviations of the data from its mean is
(A) Always positive
(B) always negative
(C) zero
(D) non-zero integer
Answer Key:
(C) zero

  
4. The mean of 100 observations is 40 and their standard deviation is 3. The sum of squares of all observations is
(A) 40000
(B) 160900
(C) 160000
(D) 30000
Answer Key:
(B) 160900

  
5. Variance of first 20 natural numbers is
(A) 32.25
(B) 44.25
(C) 33.25
(D) 30
Answer Key:
(C) 33.25

  
6. The standard deviation of a data is 3. If each value is multiplied by 5 then the new variance is
(A) 3
(B) 15
(C) 5
(D) 225
Answer Key:
(D) 225

  
7. If the standard deviation of x, y, z is p then the standard deviation of 3x + 5, 3y + 5, 3z + 5 is
(A) 3p + 5
(B) 3p
(C) p + 5
(D) 9p+ 15
Answer Key:
(B) 3p

  
8. If the mean and coefficient of variation of a data are 4 and 87.5% then the standard deviation is
(A) 3.5
(B) 3
(C) 4.5
(D) 2.5
Answer Key:
(A) 3.5

  
9. Which of the following is incorrect?
(A) P(A)>1
(B) 0 ≤ P(A) ≤ 1
(C) P(𝝓) = 0
(D) P(A) + P(Ā) = 1
Answer Key:
(A) P(A)>1

  
10. The probability a red marble selected at random from a jar containing p red, q blue and r green marbles is
(A) $\frac{q}{p+q+r}$
(B) $\frac{p}{p+q+r}$
(C) $\frac{p+q}{p+q+r}$
(D) $\frac{p+r}{p+q+r}$
Answer Key:

(B) $\frac{p}{p+q+r}$

$\frac{ }{}$
11. A page is selected at random from a book. The probability that the digit at units place of the page number chosen is less than 7 is
(A) 3/10
(B) 7/10
(C) 3/9
(D) 7/9
Answer Key:
(B) 7/10

  
12. The probability of getting a job for a person is x/3. If the probability of not getting the job is 2/3 then the value of x is
(A) 2
(B) 1
(C) 3
(D) 1.5
Answer Key:

(B) 1

   
13. Kamalam went to play a lucky draw contest. 135 tickets of the lucky draw were sold. If the probability of Kamalam winning is 1/9, then the number of tickets bought by Kamalam is
(A) 5
(B) 10
(C) 15
(D) 20
Answer Key:
(C) 15

 
14. If a letter is chosen at random from the English alphabets {a,b,...,z}, then the probability that the letter chosen precedes x
(A) 12/13
(B) 1/13
(C) 23/26
(D) 3/26
Answer Key:
(C) 23/26

 
15. A purse contains 10 notes of ₹2000, 15 notes of ₹500, and 25 notes of ₹200. One note is drawn at random. What is the probability that the note is either a ₹500 note or ₹200 note?
(A) 1/5
(B) 3/10
(C) 2/3
(D) 4/5  
Answer Key:
(D) 4/5