Page 105 - New Medley 5 Semester 2

To find the value of one item from the value of many items, we divide.

And, to find the value of a number of items from the number of many

items, we first divide and then multiply. This is called Unitary method.

Example 8 : Bananas are sold at the rate of `60 per dozen. Arjun buys
8 bananas. How much he needs to pay to the seller?

Solution: 1 dozen = 12 items

 Cost of 12 bananas = `60

\ Cost of 1 banana = `60 ÷ 12 = `5

\ Cost of 8 bananas = `5 × 8 = `40

Thus, Arjun has to pay `40.

Example 9: A car runs 84 km by using 6 L of petrol. How many
kilometres will the car run consuming 12 L of petrol?

Solution:  With 6 L of petrol, the car runs a distance of 84 km

\ With 1 L of petrol, the car runs 84 ÷ 6 km = 14 km

\ With 12 L of petrol, the car runs 12 × 14 km = 168 km

EXERCISE 2.3

A. Solve the following word problems.

1. A bottle contains 250 mL of milk. How much milk is there in 12 such
bottles?

2. The weight of a cricket ball is 150 g, find the weight of 8 balls.

3. The cost of 8 ice creams is `200. Find the cost of 10 ice creams.

4. Malika reads 287 pages in 7 days. How many pages did she read in
4 days?

5. A tray of 48 eggs costs `384. Find the cost of 10 eggs.

6. Which is cheaper—4 chocolates for `320 or 10 chocolates for `700?

7. A typist types 600 words in 30 minutes. How many words can she type

in 1 hour 10 minutes?

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