Page 37 - ICSE Math 7

EXERCISE 2.2

1. Evaluate the following.
1
1
(a) 7 + 3 – 9 (b) 5 + – 7 (c) 7 – 11 – + 5
10 10 10 8 4 12 16 32 8 24
1
1
11
13
2
1
3
5
(d) 6 + 7 – 2 (e) 4 – 2 + 3 (f) 2 + 4 – 11
5 15 20 10 3 5 9 6 3
2. Find the following.
1
1
(a) 3 of 165 m (b) 4 of 2 hours (c) 7 of 4 kg
5 7 3 15 6
1 3 1 2  5 1   1 2  3
(d) 3 × 1 × 5 (e) of  ×2  (f)  12 ×4  of 2
4 17 3 5  18 5   2 3  7
3. Find the reciprocal of the following fractions.
7 13 3 3
(a) (b) (c) 1 (d) 4
8 7 8 7
4. Reduce the following complex fractions to their simplest form.
3 1 2 1 3 1 4 1 + 2 1
(a) 2 (b) 2 (c) 4 (d) 6 3
14 4 1 6 2 1 16 7 1 8 –6 3 4
5. Simplify.

4
1
(a) 1 of   6 + 1 3 2    ÷ 8   (b) 2 22 +   2–   1 – 3  × 7    

5  3 5   15  3 7  7  14 7 10  

 3 2  2 3 1 9  7 31 5 
(c)  ÷  of 2 + –1 (d) of 11 of 5 ÷ 76 + 

 4 4  9 5 2 29  8 45 27 
1  1 { )}  3 3 1 2 11
(e) 11 – 8 +  8 – 9 5– 3+ (  (f) 5 – ×10 + 2 ÷ 1
2  2  8 7 9 35 25

1  1 4 
6 ×
(g) 7 – 3 +  – 7 –16 –14 + ( { ) }  (h) 2 – [2 – 2 ÷ {2 – 2 ÷ (2 ÷ 4)}]
2  2 19 

Word Problems
3
5
Example 17: A ribbon is 2 m long. It is divided into three parts. The first part is m long and the
5 6
6
second part is m long. Find the length of the third part of the ribbon.
5
5
6
Solution: Sum of lengths of two parts = m + m
6 5
= 5 × 5 + 6 × 6 m = 25 + 36 m = 61 m
30 30 30
3
Length of the third part = 2 m – 61 m = 13 m – 61 m
5 30 5 30
13 × 6 – 61 78 – 61 17
= m = m = m
30 30 30

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