Question

If the weight of 12 sheets of thick paper is 40 grams, how many sheets of the same paper would weigh 2 1/2 kilograms

Answer 1

40 g of thick paper contains 12 sheets
1g of thick paper contains 12/40 sheets
1 kg of thick paper contains 12/40 * 1000 sheets
5/2 kg of thick paper contains 12/40 * 1000 * 5/2 = 750 sheets
Therefore 750 sheets of thick paper weigh 2 and 1/2 kilograms

Answer 2

Solution:

Given Question:

The weight of 12 sheets of thick paper is 40 grams.

Find:

How many sheets of the same paper would weigh 2½ kilograms.

Given:

Number of sheets = 12 , x

Weight of sheets = 40 , 1500 ( in grams).

Note:

Their would be more the weight if there are more the number of sheets. hence, the sheets and the weight are directly proportional to each other.

Calculations:

→ 12/40 = x/2500

or → 12 × 2500/400 = x

or → 750 = x

Therefore, 750 would be the required number of sheets of paper.

Alternate method:

Two quantities (x) and (y) they differ from direct proportion (x = Ky) or (x/y = k).

k = number of sheets/weight of sheets of in grams:

→ ( 12/40 = 3/10 ).

→ x = 2½ kg = (2500 g).

→ x = ky , x = 3/10 × 2500 = 7500.

Therefore, 750 sheets of paper would weight 2½ kg.