1Book Back Questions24 questions
Q.1Use a variable to write the rule, which gives the number of ice candy sticks required to make the following patterns. v
Answer:(a) No of ice candy sticks used = 3 × n = 3n
(b) No of ice candy sticks used = 4 × n = 4n
Q.2The teacher forms groups of five students in a class. How many students will be there in ‘p’ groups?v
Answer:No of students in a group = 5
No of students in ‘p’ groups = 5 × p = 5p
Q.3Arivazhagan is 30 years younger than his father. Write Arivazhagan’s age in terms of his father’s age.v
Answer:Let Arivazhagan’s father’s age be x years
According to the problem,
Arivazhagan’s age = (x – 30) years
Q.4If ‘u’ is an even number, how would you represent (i) the next even number? (ii) the previous even number?v
Answer:(i) Difference between two even numbers = 2
Given that ‘u’ is an even number.
Next, the even number is u + 2.
(ii) Previous even number is u – 2.
Objective Type Questions
Q.5Variable means that itv
- A. can take only a few values
- B. has a fixed value
- C. can take different values
- D. can take only 8 values
Answer:(c) can take different values
Q.6Radha is ‘x’ years of age now. 4 years ago, her age wasv
- A. x – 4
- B. 4 – x
- C. 4 + x
- D. 4x
Q.7The number of days in ‘w’ weeks isv
- A. 30 + w
- B. 30w
- C. 7 + w
- D. 7w
Q.8Find in the blanks. (i) The algebraic statement of ‘f’ decreased by 5 is _______ (ii) The algebraic statement of ‘s’ divided by 5 is _______ (iii) The verbal statement of ‘2m – 10’ is _______ (iv) If A’s age is ‘n’ years now, 7 years ago A’s age was ______ (v) If ‘p – 5’ gives 12 then ‘p’ is ______v
Answer:(i) f – 5
(ii) \(\frac { s }{ 5 }\)
(iii) 10 less than 2 times m (or) Take away 10 from the product of 2 and m
(iv) n – 7
(v) 17
Hint: p – 5 = 12 ⇒ n = 12 + 5 = 17
Q.910 more to three times ‘c’ is ‘3c + 13’.v
Answer:False
Hint: 3c + 10
Q.10If the cost of 10 rice bags is ‘t’, then the cost of 1 rice bag is \(\frac { t }{ 10 }\)v
Q.11The statements ‘x’ divided by 3 and 3 divided by ‘x’ are the same.v
Q.12The product of ‘q’ and 20 is ’20q’v
Q.137 less to 7 times ‘y’ is ‘7 – 7y’v
Q.14Express the following verbal statement to an algebraic statement. (i) ‘t’ is added to 100 (ii) 4 times ‘q’ (iii) 8 is reduced by ‘y’ (iv) 56 added to 2 times ‘x’ (v) 4 less to 9 times of ‘y’v
Answer:(i) t + 100
(ii) 4q
(iii) 8 – y
(iv) 2x + 56
(v) 9y – 4
Q.15Express the following algebraic statement to a verbal statement. (i) x ÷ 3 (ii) 5n – 12 (iii) 11 + 10x (iv) 70sv
Answer:(i) x divided by 3.
(ii) 12 less to 5 times n.
(iii) 11 added to 10 times x
(iv) 7 times s.
Q.16The teacher asked two students to write the algebraic statement for the verbal statement “8 more than a number”. Vetri wrote ‘8 + x’ but Maran wrote ‘8x’. Who gave the correct answer?v
Answer:Let the number be x; 8 more than the number = 8 + x.
Vetri gave the correct answer as 8 + x.
Q.17Answer the following questions. (i) If ‘n’ takes the value 3 then find the value of ‘n + 10’? (ii) If ‘g’ is equal to 300 what is the value of ‘g – 1’ and ‘g + 1’? (iii) What is the value of ‘s’, if ‘2s – 6’ gives 30?v
Answer:(i) n = 3
n + 10 = 3 + 10 = 13(ii) g = 300
g – 1 = 300 – 1
= 299
g + 1 = 300 + 1
=301
(iii) 2s – 6 = 30
2s = 30 + 6
2s = 36
s = 36/2
s = 18
Q.18The value of ‘y’ in y + 7 = 13 isv
- A. y = 5
- B. y = 6
- C. y = 7
- D. y = 8
Answer:(b) y = 6
Hint: y = 13 – 7 = 6
Q.196 less to ‘n’ gives 8 is represented asv
- A. n – 6 = 8
- B. 6 – n = 8
- C. 8 – n = 6
- D. n – 8 = 6
Q.20Complete the following pattern. 9 – 1 = 98 – 21 = 987 – 321 = 9876 – 4321 = 98765 – 54321 = What comes next?v
Answer:9 – 1 = 8
98 – 21 = 77
987 – 321 = 666
9876 – 4321 = 5555
98765 – 54321 = 44444
Next will be 987654 – 654321 = 333333
Q.21A piece of wire is ‘12s’ cm long. What will be the length of the side if it is formed as (i) an equilateral triangle. (ii) a square?v
Answer:(i) An equilateral triangle has 3 equal sides.
Length of the wire = ‘12s’ cm
Length of each side = \(\frac{12 s}{3}\) cm.
Length of each side of the triangle = 4s cm
(ii) A square has four equal sides.
Length of each side \(\frac{12 s}{4}\) cm
Length of each side of the square 3s cm
Q.22The table given below shows the results of the matches played by 8 teams in a kabaddi championship tournament. Find the value of all the variables in the table given above.v
Answer:k = 3, m = 1, n = 10, a = 9, b = 6, c = 4, x = 4, y = 9Challenging Problems
Q.23Gopal is 8 years younger than Karnan. If the sum of their ages is 30, how old is Karnan?v
Answer:Let the age of Kaman be x years
Gopal’s age = x – 8
Ace to the problem, x + x – 8 = 30
2x – 8 = 30
2x = 30 + 8
2x = 38
x = \(\frac{38}{2}\)
x = 19
Age of Kaman = 19 years
Q.24The rectangles made of identical square blocks with varying lengths but having only two square blocks as width are give below (i) How many small size squares are there in each of the rectangles P,Q, R and S? (ii) Fill in the boxes. v
Answer:(i) P = 2; Q = 8; R = 6; S = 10