NCERT Solutions Class 6 Mathematics Algebra Ex 11.1

Question: 2. We already know the rule for the pattern of letter L, C and F. Some of the letters from Q.1 (given above) give us the same rule as that given by L. Which are these? Why does this happen?

Answer :
The letter ‘T’ and ‘V’ that has 2n pattern since 2 matchsticks are used in all these letters.

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 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 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 for the number of students)

Answer :
Number of students = s

Number of pencils to each student = 5

Therefore, total number of pencils needed are = 5s

Question: 6. A bird flies 1 kilometer in one minute. Can you express the distance covered by the bird in terms of its flying time in minutes? (Use for flying time in minutes)

Answer :
Time taken by bird = minutes

Speed of bird = 1 km per minute

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

Question: 7. Radha is drawing a dot Rangoli (a beautiful pattern of lines joining dots with chalk powder as in figure). She has 8 dots in a row. How many dots will her Rangoli have for rows? How many dots are there if there are 8 rows? If there are 10 rows?

Answer :
Number of dots in each row = 8 dots

Number of rows = r

Therefore, total number of dots in r rows = 8r

When there are 8 rows, then number of dots = 8 x 8 = 64 dots

When there are 10 rows, then number of dots = 8 x 10 = 80 dots

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 :
Radha’s 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 how many laddus did she make?

Answer :
Number of laddus gave away = l

Number of laddus remaining = 5

Total number of laddus she make = (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 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 matchstick. 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.)