Question

4. Is there any change in mass when a substance changes its state? Explain with
exemple (AS1)​

Answer 1

Answer:

When a substance changes its state , there will not be any change in the mass of substance . For example , if we change 100 grams of water (liquid) to ice(solid) , the mass of ice will be same i.e., 100 grams . This shows there is no change in the mass even if a substance changes its state.

Answer 2

Explanation:

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✤ Required Answer:

✒ GiveN:

Cost price of a fan = Rs. 1200

Gain % = 8 %

✒ To Find:

Selling price of the fan....?

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✤ How to solve?

For solving this question, Let's note down some important formulae:

Selling price = Cost price + Gain/Profit

And, Profit % = Profit/CP × 100

Or else, Direct formula,

\large{ \boxed{ \rm{SP = \frac{CP(100 + p\%)}{100} }}}

SP=

100

CP(100+p%)

☃️ So, Let's try both the formulae, and solve the question

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✤ Solution:

Method 1:

We have,

Cost price = Rs. 1200

Gain % = 8 %

Finding gain/profit,

➝ Gain % = Gain/CP × 100

➝ 8 = Gain/1200 × 100

➝ 8 = Gain/12

➝ Gain = Rs. 96

Finding Selling price,

➝ Selling price = Cost price + Gain

➝ Selling price = Rs. 1200 + Rs. 96

➝ Selling price = Rs. 1296

☀️ Selling price of the fan = Rs. 1296

Method 2:

By using shortcut formula,

➝ Selling price = Cost price(100 + Gain%)/100

➝ Selling price = 1200(100 + 8)/100

➝ Selling price = 12 × 108

➝ Selling price = Rs. 1296

☀️ Here also, SP of the fan = Rs. 1296 only.

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