Aptitude Chapter-11

Bodhak competitive bank exam ratio proportion this tutorial is useful to prepare for Bank Exams, Groups Exams, Interviews of MNC & Exams like CRT, CAT, MAT, GRE, GATE  etc. in this chapter we will discuss RATIO AND PROPORTION. We will see how o solve through equations and through shortcut methods.

 

RATIO AND PROPORTION:

Ratio: The comparison of two similar quantities.

Proportion: The equality of two ratios.

A:B=C:D then D is forth proportion.

A:B=B:C then C is third proportion.

 

competitive bank exam ratio proportion

A:B=C:D then D is called forth proportion.

A:B=B:C then C is third proportion.

The duplicate ratio of A, B is:  a^2: b^2

The sub duplicate ratio of A,B is      :  sqrt(a) : sqrt(b)

The mean proportion of A, B is: sqrt(ab)

The triplicate ratio of a,b is:a^3: b^3

 

The fourth proportional to 9,12,36  is?

Solution:

A:B  =C:D Then D is called fourth proportional

A=9,  B=12,  C=36,  D=?

9:12  =  36:D

(9/12)=(36/D)=(1/12)=(4/D)

D  =  12×4  =  48

Find the third proportional to 8,20?

Solution:

A:B  =  B:C then C is called third proportional

A=8,  B=20,  C=?

8:20  =  20:C

c=50

Example:

A sum of money is distributed among A,B,C, D in the proportion of 8:10:7:5. if A gets rs.1500 more then D then C Share is?

Solution:

A:B:C:D  =  8:10:7:5

A=8, D=5

8-5=1500

3=1500

1=500

C=7  =  7×500  =  3500

Example:

Two numbers are in the ratio 1:2. If 7 is added to both the ratio 3:5. The lowest number is?

Solution:

Two numbers are in the 1:2

So one number   =x

another number   =2x

Add 7 to both numbers

(x+7)/(2x+7)=3/5

5(x+7)  =  3(2x+7)

5x+35  =  6x+21

6x-5x  =  35-21

X=14  2x  =  2X14  =  28     So lowest number is 14