# Unitary method

We daily go to the market and buy something. Sometimes shopkeeper tells us about total cost instead of cost of single object.

For example:

• Rohan went to market to buy bananas. The shopkeeper told him that, bananas are 60 rs per dozens. Then Rohan felt in thinking that single banana is of how much cost.
• This types of examples are solved by using unitary method. First we find the cost value of each object and then we find the cost value of given number of objects.
• In this way, unitary method is helpful for determining price of good, the distance travelled by any vehicle during given interval of time and mostly to determine profit and loss.

### For example:

1) Rohan buys 1 dozen bananas for 60 rs. Then what is the cost of single banana. And what is the cost of 18 bananas.

Ans:

Here, 1 dozen bananas means 12 bananas.

12 bananas = 60 rs

1 banana = 60/12= 5 rs.

Thus, cost of one banana is 5 rs.

And, hence cost of 18 bananas is = 18*5= 90 rs

2) Rima working in IT company and she get yearly 5 lakh package. What is her monthly payment?

Ans:

The one year has total months 12.

Hence, 12 months = 4,00,000

Thus, 1 month = 4,00,000/ 12 = 33,333.33 rs

Hence, Rima get monthly payment as 33,333.33Rs.

3) If the cost of 7 apple is 140. Then what is the cost of 12 apple?

Ans:

Here, cost of 7 apple = 140

Cost of one apple = 140/7 = 20

Hence, the cost of 12 apple = 12*20 = 240

Hence, the cost of 12 apple will be 240 Rs.

4) Sachin went to book shop and taken 7 copies of science book for his classmates also. He had given 560 Rs to shopkeeper. Then how much rupees will he receive from his each friend.

Ans:

Here, 7 books cost = 560

Hence, 1 book cost = 560/7 = 80

Thus, Sachin will have to take 80 Rs. From his each friend.

5) Sam went to vegetable market and he had taken 500 g potatoes in 30 Rs. Then what is the cost of 1000 g potatoes.

Ans:

Here, 500 g = 30

Hence, 100 g = 30/5 = 6

Thus, 1000 g has cost = 10*6 = 60

Hence, the cost of 1000 g i.e. 1 kg potatoes is 60 Rs.

6) Heena went to grocery shop and taken 2.5 kg sugar in 150 Rs. Then what is the cost of 1 Kg sugar.

Ans:

Here, 2.5 kg = 150

That is 2500 g = 150

Hence, 100 g = 150/25 = 6

Thus, 1 kg = 1000 g has cost = 10*6 = 60

Hence, the cost of 1kg sugar is 60 Rs.

7) If a car travels 30 km in 90 minutes then to cover 120 km distance what should be the time required by the car.

Ans:

Here, 30 km = 90 min

Hence, 1 km = 90/30 = 3 min

Hence, to cover 120 km the time required is = 120*3= 360 min

Thus, the car should take 360 min i.e. 6 hours to cover distance 120 km.

In this way, we can find first cost of unit object and from that we can find the cost of given number of object. This method is called as the unitary method.

Updated: July 24, 2021 — 11:23 pm