**(avalia-blackboard)**

Constant Product Rule

Constant Product Rule

**We deal with these problems often**

**=**

**=**

CPR Table

Lets look at the rule !

If there are 2 variables and their product is constant, then -

a (1/x ) increase in one variable will lead to (1/x+1) decrease in the other.

1/(x)

=

1/(x+1)

Look at the table again -

Help these 5 People !

Price of coffee is increased by 25% but the Sweetie family wants to keep the expenditure same, by what % should we decrease our consumption?

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My income is 37.5% less than my friend Tom's. Then Tom’s income is how much % more than mine?

A quick glance back

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I've reduced my aircraft's speed by 1/4th , now my journey time will increase by what % ?

Hi, its the Sweeties here, we are spending 600 on coffee every month. Now, that the price has gone down by 20% and we are able to buy 5 kg more. Can you remind us the original price of coffee (in kg)?

I spends rs.54 on eggs every month. Price of eggs decreased by 20% and I can buy 10 eggs more now. What do you think is the reduced price per dozen?

Writing at 3/4th of my usual speed, I finished the above question paper 20 minutes late. Had I written the answers at my regular speed, I could have finished the whole paper in how many hours?

Earlier we used to ask 560 questions for 2900 marks. Now we want to decrease number of questions by 20% but want to keep total marks same as before. How many marks each will the new questions carry?

Walking at 6/7th of my usual speed, I am 25 minutes late for office, what is my usual time to cover this distance to office? (In hours)

You are the product manager of SONY Bravia Televisons.The surface area of your TV is A. Now that you have to come up with the flatter version of it, the breadth of the TV is increased by 40%. By how much should the length be reduced such that the surface area remains A?

1/x 1/(x+1)

1/x 1/(x-1)

n/x n/(n+x)

20%

50%

33%

11%

33.33%

Password: black123

Rs. 30/kg

6.47 Marks

1 hour

12.96/dozen

Video Explanations

Areas of CPR application:

Speed and Distance

Pipes and Cisterns

Work and Time

Area and others

60%

2 hours and 30 min

16.67%

Price of coffee has increased by 25%,

Expenditure has to be the same.

With the rule Increase in 25% -> 1/4 => 1/(4+1) decrease

1/4 increase => in 1/5 decerase => 20%