### NCERT Solutions For Class 6 Maths Chapter 11 Algebra Ex 11.4

**Ex 11.4 Class 6 Maths Question 1.**

**Answer the following:**

**(a) Take Sarita’s present age to bey years.**

**(i) What will be her age 5 years from now?**

**(ii) What was her age 3 years back?**

**(iii) Sarita’s grandfather is 6 times her age. What is the age of her grandfather?**

**(iv) Grandmother is 2 years younger than grandfather. What is grandmother’s age?**

**(v) Sarita’s father’s age is 5 years more than 3 times Sarita’s age. What is her father’s age?**

**(b) The length of a rectangular hall is 4 metres less than 3 times the breadth of the hall. What is the length, if the breadth is b metres?**

**(c) A rectangular box has height h cm. Its length is 5 times the height and breadth is 10 cm less than the length. Express the length and the breadth of the box in terms of the height.**

**(d) Meena, Beena and Leena are climbing the steps to the hill top. Meena is at step s, Beena is 8 steps ahead and Leena 7 steps behind. Where are Beena and Meena? The total number of steps to the hill top is 10 less than 4 times what Meena has reached. Express the total number of steps using s.**

**(e) A bus travels at v km per hour. It is going from Daspur to Beespur. After the bus has travelled 5 hours, Beespur is still 20 km away. What is the distance from Daspur to Beespur? Express it using v.**

**Solution:**

(a) Sarita’s age is given y years.

(i) After 5 years from now, her age will be (y + 5) years.

(ii) 3 years back from now, she was (y – 3) years of age.

(iii) Age of her grandfather = 6y years.

(iv) Age of her grandmother = (6y – 2) years.

(v) Sarita’s father’s age = (3y + 5) years.

(b) Let T be the length of the rectangular hall

∴ length = (3b – 4) metre

Where b represents the breadth.

(c) Height of the rectangular box is ‘h’

∴ Length = 5h cm

and Breadth = (5h – 10) cm.

(d) Meena is at step s.

∴ Beena is at (s + 8) steps and Leena is at (s – 7) steps.

Total number of steps on to the hill top = (4s – 10)

(e) Distance travelled by Bus in 5 hours = 5v km.

∴ Distance from Daspur to Beespur = (5v + 20) km.

**Ex 11.4 Class 6 Maths Question 2.**

**Change the following statements using expressions into statements in ordinary language.**

**(For example, Given Salim scores r runs in a cricket match, Nalin scores (r + 15) runs. In ordinary language – Nalin scores 15 runs more than Salim.**

**(a) A notebook costs ₹p. A book costs ₹3p.**

**(b) Tony puts q marbles on the table. He has 8q marbles in his box.**

**(c) Our class has n students. The school has 20n students.**

**(d) Jaggu is 2 years old. His uncle is 42 years old and his aunt is (4z – 3) years old.**

**(e) In an arrangement of dots there are r rows. Each row contains 5 dots.**

**Solution:**

(a) A book costs 3 times the cost of a notebook.

(b) Tony has 8 times the number of marbles put on the table by him.

(c) The school has 20 times the number of students in a class.

(d) Jaggu’s uncle’s age is 4 times his age and his aunt’s age is 3 years less than the age of his uncle.

(e) Number of dots in a row is 5 times the number of rows.

**Ex 11.4 Class 6 Maths Question 3.**

**(a) Given Mannu’s age to be x years, Can you guess what (x – 2) may show?**

**(Hint: Think of Mannu’s younger brother) can you guess what (x + 4) may now? What (3x + 7) may show?**

**(b) Given Sara’s age today to bey years. Think of her age in the future or in the past.**

**What will the following expression indicate?**

**y + 7, y – 3, y + 4 1/2 , y – 2 1/2 .**

**(c) Given n students in the class like football, what may 2n show? What may n/2 show?**

**(Think of games other than football).**

**Solution:**

(a) Given that Mannu’s age = x years.

∴ (x -2) years may be the age of her younger brother or younger sister.

(x + 4) years show the age of her elder brother or elder sister.

(3x + 7) years may be the age of her father, mother or uncle.

(b) y represents the age of Sara in years.

∴ y + 7 shows her future age.

y – 3 shows her past age.

y + 4 1/2 show her future age i.e., the age after z

four and half years.

y – 2 1/2 shows her past age i.e., the age before two and half years.

(c) Number of students who like football = n

∴ 2n = twice the number of football players may like to play cricket.

and n/2 = half of the number of football 2

players may like to play basket ball.