Page 224 - Start Up Mathematics_6

Number of polygons 1 2 3 4 5 10 20 25 n
Number of matchsticks 5 9 … … … … … … …

5. Complete the following table. By
inspection method, find the solution x 1 2 3 4 5 6 7
of the equation 2x – 9 = 5. 2x – 9 ... ... ... ... ... ... ...
x
6. In a classroom there are x rows. If each row has 3 benches and each bench can accommodate

4 students, find the seating capacity of the classroom.
7. Pick the solution from the values given in the bracket next to the equation. Show that the
other values do not satisfy the equation.
q
(a) = 7 ; (7, 2, 10, 14) (b) 3x + 16 = 4 ; (3, –3, 4, –4)
2
Thinking Skills

1. The following patterns of huts are made using matchsticks.

(a) Write down the rule to find the number of matchsticks in a pattern involving 5 huts,
10 huts and so on to n huts.

(b) How many huts will be involved in a pattern having 111 matchsticks?
2. Complete the table given below, based on the pattern of dots and line segments. Also generalize
and find the expression for the number of dots and segments used in case of n squares.

Number of squares 1 2 3 4 5 10 n
Number of dots 4 8 … … 20 … …
Number of line segments 4 9 … … … … …
3. You are taking some friends for a movie and want to treat them with pizza. The cost of the
movie ticket is ` 120 and the pizza costs ` 30. Let n represent the number of friends, then

(a) write an expression for the total amount you will spend.
(b) if n = 5, what will be your total expenditure?

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