Dear Readers ,
Today I am going explain about ratios. Ratios are the one of the important topics in Quantitative Aptitude section. It's mainly useful in Ages,Partnership problems.
Definition : A ratio says how much of one thing there is compared to another thing.
Example : Syam have total 12 chocolates , he distributed these chocolates to his friends ram and barath 4 and 8 respectively.
Ram got 4 and barath got 8, here the ratio of chocolates distributed = 4: 8 = 1:2
Type 1 : Find Ratio of A:B:C , If A:B = 2:3 and B:C = 4:5 ?
Solution :
First find the common one in given ratios
Here B is common in given ratios , try to equal the that common term
In one ratio B is 3 and in another B is 4 . Take LCM of 3 and 4 its 12.
Multiple both ratio with as per LCM ,
Ratio 1 = 2:3 *4 = 8:12
Ratio 2 = 4:5 * 3 =12:15
Now the common terms are equal , A:B:C = 8:12:15
Type 2 : A:B = 2:3 , B :C = 4:5 and C:D = 1:3. Find Ratio of A:B:C:D ?
Solution :
In this we have 2 terms common one is B and another one C.
As per step-1 multiple those three digits , you will get A = 2*4*1 =8
As per step-2 multiple those three digits , you will get B = 3*2*1 =6
As per step-3 multiple those three digits , you will get C = 3*5*1= 15
As per step-4 multiple those three digits , you will get D = 3*5*3=45
A: B:C:D = 8:12:15:45
Type - 3 : A : B = 3:4 after 4 years its become 7:9 , Find A and B values initially ?
Solution :
Find the difference between A and B = 4-3 = 1
Find the difference between A and B after 4 years = 9-7=2
Now multiple 3:4with 2 and similarly 7:9 with 1
A : B = 3:4 *2 = 6:8
A:B after 4 years = 7:9 *1 = 7: 9
Now check difference between Before and After difference A .
A = 7-6 = 1
From that 1 Unit -------- 4
6 units ------ A
A = 6*4=24
Similarly B = 32
