These NCERT Solutions for Class 6 Maths Chapter 11 Algebra Ex 11.1 Questions and Answers are prepared by our highly skilled subject experts.

## NCERT Solutions for Class 6 Maths Chapter 11 Algebra Exercise 11.1

Question 1.

Find the rule which gives the number of matchsticks required to make the following matchstick patterns. Use a variable to write the rule.

Answer:

Question 2.

We already know the rule for the pattern of letters L, C and F. Some of the letters from Q.l (given above) give us the same rule as that given by L. Which are these? Why does this happen?

Answer:

The rules to find the number of matchsticks for:

The letter L is 2n The letter C is 3n

The letter V is 2n The letter U is 3n

The letter T is 2n The letter F is 4n

∴ It is same for L, V and T. The number of matchsticks required in each of them is 2.

Question 3.

Cadets are marching in a parade. There are 5 cadets in a row. What is the rule which gives the number of cadets, given the number of rows? (Use n for the number of rows.)

Answer:

Number of rows = n

Cadets in each row = 5

Therefore, total number of cadets = 5n.

Question 4.

If there are 50 mangoes in a box, how will you write the total number of mangoes in terms of the number of boxes? (Use b for the number of boxes.)

Answer:

Number of boxes = b

Number of mangoes in each box = 50

Therefore, total number of mangoes = 50b.

Question 5.

The teacher distributes 5 pencils per student. Can you tell how many pencils are needed, given the number of students? (Use s for the number of students.)

Ans. Number of students = s

Number of pencils to each student = 5

Therefore, total number of pencils needed are = 5s.

Question 6.

A bird flies i kilometer in one minute. Can you express the distance covered by the bird in terms of its flying time in minutes? (Use t for flying time in minutes.)

Answer:

Time taken by bird = t minutes

Speed of bird = 1 km per minute

Therefore, Distance covered by bird = speed × time = 1 × t = t km.

Question 7.

Radha is drawing a dot Rangoli (a beautiful pattern of lines joining dots with chalk powder. She has 9 dots in a row. How many dots will her Rangoli have for r rowrs? How many dots are there if there are 8 rows? If there are 10 rows?

Answer:

1 row = 9 dots

r rows = (9*r) dots

= 9r dots

8rows = 9*8 = 72dots

10rows = 10*9 = 90dots

Question 8.

Leela is Radha’s younger sister. Leela is 4 years younger than Radha. Can you write Leela’s age in terms of Radha’s age? Take Radha’s age to be × years.

Answer:

Radhas age = x years

Therefore, Leela’s age = (x – 4) years

Question 9.

Mother has made laddus. She gives some laddus to guests and family members; still 5 laddus remain. If the number of laddus mother gave away is l, how many laddus did she make?

Answer:

Number of laddus gave away = l

Number of laddus remaining = 5

Total number of laddus = (l + 5)

Question 10.

Oranges are to be transferred from larger boxes into smaller boxes. When a large box is emptied, the oranges from it fill two smaller boxes and still 10 oranges remain outside. If the number of oranges in a small box are taken to be x, what is the number of oranges in the larger box?

Answer:

Number of oranges in one box = x

Number of boxes = 2

Therefore, total number of oranges in boxes = 2x

Remaining oranges =10

Thus, number of oranges = 2x + 10

Question 11.

(a) Look at the following matchstick pattern of squares. The squares are not separate. Two neighbouring squares have a common match- stick. Observe the patterns and find the rule that gives the number of matchsticks in terms of the number of squares. (Hint: if you remove the vertical stick at the end, you will get a pattern of Cs.)

(b) The given figure gives a matchstick pattern of triangles. Find the general rule that gives the number of matchsticks in terms of the number of triangles.

Answer:

13 matchsticks

If we remove 1 from each then they makes table of 3, i.e., 3, 6, 9, 12…

So the required equation = 3x + 1, where x is number of squares.

If we remove 1 from each then they makes table of 2, i.e., 2, 4, 6, 8…

So the required equation = 2x +1, where x is number of triangles.