Page 81 - Start Up Mathematics_7

2. Compare the following rational numbers by putting <, >, or =:
5 –3 3 1 2 –14
(a) (b) (c)
4 4 4 5 3 –21

3. Write two rational numbers between each pair:
–6 4
(a) and (b) –2 and 1 (c) 3.2 and 3.3
10 5
4. Write equivalent rational numbers with the given denominators:
–9 –3
(a) = (b) =
13 39 7 21
2 –3 3 18
5. Find the sum of: (a) + (b) +
15 4 4 20
5 –9 3 7
6. Subtract: (a) form (b) form
8 10 4 8
6 –4 13 21
7. Multiply: (a) × (b) ×
11 7 19 17
2 5 –3 4
8. Divide: (a) ÷ (b) ÷
3 9 5 15
–6
9. Express as a rational number with:
10
(a) numerator 18 (b) denominator 5 (c) numerator –12

2 –3
10. By taking x = and y = , verify the following:
5 10
(a) |x + y| ≤ |x| + |y| (b) |xy| = |x| . |y|
3 2
11. Represent on a number line: (a) (b) –1
4 3

Thinking Skills

4
1. Find a rational number which in its standard form is equal to and the sum of its numerator
5
and denominator is 27.
2. Yasmin claims “If we have two positive rational numbers, the one with the greater denominator
is smaller”. Justify or contradict by giving examples?
1
3. Dr Max, a professional trader, bought 225 shares of a company at ` 23 a share. A month
3 2
later he sold them at ` 31 a share. How much did Dr Max gain on the transaction?
4
2
4. A cricketer made 253 runs in the current IPL season. This is 9 th more than what he made
in the previous IPL last year. How many runs did he make last year?

1
5. In a super market, the cost of a table lamp is ` 870, on which th is off. The same table
5
1
lamp is available at an electric shop for ` 920 with a discount of th. From where should
one buy the lamp? What is the difference in prices? 10

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