# Problems on Unitary Method Using Inverse Variation

We will learn how to solve problems on unitary method using inverse variation.

We know, if two quantities are related in such a way that increase in one quantity causes corresponding decrease in the other quantity and vice versa, then such a variation is called an inverse variation or indirect variation.

Solved problems on unitary method using inverse variation:

1. 12 typists working for 4 hours to type a book in 18 days. In how many days 4 typists will work for 8 hours to type same book?

Solution:

This is a situation of indirect variation.

12 typists working for 4 hours type a book in 18 days

1 typist working for 4 hours types a book in 18 × 12 days.

1 typist working for 1 hour types a book in 18 × 12 × 4 days.

4 typists working for 1 hour type a book in (18 × 12 × 4)/4

4 typists working for 8 hours type a book in (18 × 12 × 4)/(4 × 8) days.

Therefore, 4 typists working for 8 hours type a book in 27 days.

2. 16 men can build a wall in 56 hours. How many men will be required to do the same work in 32 hours?

Solution:

This is a situation of inverse variation

More the number of men, the faster will they build the wall.

In 56 hours, the wall is built by 16 men.

In 1 hour, the wall is built by 16 × 56 men.

In 32 hours, the wall is built by (16 × 56)/32 men

Therefore, in 32 hours, the wall is built by 28 men.

3. If 72 workers can do a piece of work in 40 days, in how many days will 64 workers complete the same work?

Solution:

This is a situation of indirect variation.

Less workers will require more days to complete the work.

72 workers can do the work in 40 days

1 worker can do the same work in 72 × 40 days

64 workers can do the same work in (72 × 40)/64

Therefore, 64 workers can do the same work in 45 days.

Problems Using Unitary Method

Situations of Direct Variation

Direct Variations Using Unitary Method

Direct Variations Using Method of Proportion

Inverse Variation Using Unitary Method

Inverse Variation Using Method of Proportion

Problems on Unitary Method using Direct Variation

Problems on Unitary Method Using Inverse Variation

Didn't find what you were looking for? Or want to know more information about Math Only Math. Use this Google Search to find what you need.

## Recent Articles

1. ### Decimal Place Value Chart |Tenths Place |Hundredths Place |Thousandths

Jul 19, 24 03:26 PM

Decimal place value chart are discussed here: The first place after the decimal is got by dividing the number by 10; it is called the tenths place.

2. ### Definition of Decimal Numbers | Decimal Part | Decimal Point |Examples

Jul 19, 24 11:13 AM

Definition of decimal numbers: We have learnt that the decimals are an extension of our number system. We also know that decimals can be considered as fractions whose denominators are 10, 100, 1000

3. ### Addition and Subtraction of Fractions | Solved Examples | Worksheet

Jul 19, 24 02:00 AM

Addition and subtraction of fractions are discussed here with examples. To add or subtract two or more fractions, proceed as under: (i) Convert the mixed fractions (if any.) or natural numbers

4. ### Fractions in Descending Order |Arranging Fractions an Descending Order

Jul 19, 24 02:00 AM

We will discuss here how to arrange the fractions in descending order. Solved examples for arranging in descending order: 1. Arrange the following fractions 5/6, 7/10, 11/20 in descending order. First…

5. ### Fractions in Ascending Order | Arranging Fractions | Worksheet |Answer

Jul 19, 24 01:59 AM

We will discuss here how to arrange the fractions in ascending order. Solved examples for arranging in ascending order: 1. Arrange the following fractions 5/6, 8/9, 2/3 in ascending order. First we fi…