Q2 of 38 Page 8

Let's arrange sticks in a new arrangement and find the number of sticks required in the n-th position.

The new arrangement would be



Sticks in first arrangement (a) = 2


Sticks in second arrangement = 5


Common Difference (d) = 5 – 2 = 3


Sticks in n-th position = a + (n – 1) d


= 2 + (n – 1) (3)


= 2 + 3n – 3


= 3n – 1


the sticks required in n-th position are “3n – 1”


More from this chapter

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8

The length, breadth and height of the club-house of our village is 7.2 m., 5.5 m. and 4.2 m respectively. There is a door in the room of length 3 m. and breadth 1.8 m. and two windows each of length 2.25 m. and breadth 1.8 m

A. Let’s measure the area of the floor of the club-house and calculate the total expenditure of cementing the floor at the rate of Rs. 62/m2.


B. Let’s measure the area of the inner wall excluding the door and window.


C. Let’s measure the area of the ceiling of the room.


D. Let’s calculate the total expenditure of whitewashing the inner wall and ceiling except the door and windows at the rate of Rs 12/m2.


 1

Let's find out the total number of match sticks required in the n-th position of the previous three types of arrangements.

 1

Let's fill up the table below:

 1

Let’s write the number of match sticks in n-th position (n is a positive integer) in each arrangement:

i.


ii.


iii.