Page 42 - Start Up Mathematics_7

EXERCISE 2.4

7 3 6 7
1. Find the reciprocals of : (a) (b) (c) (d)
3 5 7 3
1
3
7
2. Find: (a) 18 ÷ (b) 14 ÷ (c) 6 ÷ 2 (d) 25 ÷ 2 1
4 5 3 7
1 2 7 1 7 3 10
3. Divide: (a) 3 by (b) by 4 (c) 3 by 2 (d) 100 by
4 3 8 2 15 5 3
1
4. A wire of length 6 m is cut into 13 pieces of equal length. Find the length of each piece.
2
3 1
5. By what number should 4 be multiplied to get 6 ?
4 4
3
6. The cost of 4 kg apples is ` 300. What is the rate of apples per kg?
4
3
7. A bucket contains 18 litres of water. How many litres jugs can be filled from the bucket?
5
1
8. In a hostel’s mess, each student gets litre of milk everyday. If the total consumption of
3
2
milk is 87 litres per day, how many students are there in the hostel?
3

9. Use the correct order of operations to calculate:
1 1 1 1 1 1
(a) 2 + ÷ – (b) ÷ +
2 3 5 3 2 4
7
1
1
1
1
(c) 3 + ÷ 2 – (d) 5 × 4 – ÷ 2 1
2 2 2 2 2 3
Reason It Out!

Write down the next three numbers after recognizing the pattern in each series.
3 5 1
(a) 2 , 2, 1 , 1 , _______, _______, _______
8 8 4
1 1 1
(b) 9, 4 , 2 , 1 , _______, _______, _______
2 4 8
7 7 7 7
(c) , , , , _______, _______, _______
64 32 16 8
4
(d) 100, 20, 4, , _______, _______, _______
5
11 5 9 4 7
, , ,
(e) 13 6 11 5 9 _______, _______, _______
, ,
3 1
[Hint: (a) Subtract from each. (b) Multiply each by .
8 2
(c) Multiply each by 2. (d) Divide each by 5.
(e) Subtract 1 from the numerator as well as the denominator.]

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