Monday, January 27, 2014

Tricks to solve Ratio and Proportion Problems

Posted by Jasleen Behl
Today I'm going to discuss a very helpful trick of ratio and proportion of Quantitative Aptitude section. I'm sure this would be very helpful for you and this trick will save your more than half time, you generally take to solve the question.

Ratio and Proportion

  • Some facts of Ratio and proportion
  • Ratio is written as 2:3, where 2 and 3 are known as terms.
  • First term i.e. 2 is known as Antecedent.
  • Second term i.e. 3 is known as Consequent.
  • `2^2`: `3^2` is known as duplicate ratio of 2:3.
  • `2^3`:`3^3` is known as triplicate ratio of 2:3.
  • `sqrt2`: `sqrt3` is sub-duplicate ratio of 2:3.
  • `a^(1/3)` : `b^(1/3)` is sub-triplicate ratio of 2:3.

Ratio and Proportion Trick

Let me tell you one example which can be solved in 30 sec if you use this trick

Example: If A:B = 3: 4, B: C = 2: 3 and C:D = 5:7, then find A:B:C:D.
Solution: General method of solving this question is very lengthy, So let me tell me tell you how can we calculate it easily.

See how it is simple, you just need to remember the pattern and if you notice it, it is really simple .
Last and first steps are just the straight lines. So, what is left, just the middle pattern.
If I talk about only three terms i.e. A, B and C. Then the pattern will be much easier. Lets see how,

Let us do an example of 5 terms:

Example: If A: B = 3: 4, B: C = 4: 5, C: D = 1: 2 and D: E = 3: 4, Find A: B: C: D: E.

Solution: Similarly, in this case, make the same pattern as in above cases:

Take a pen and try to make it yourself first or do it step by step by looking the solution. then only you can learn this technique.

 
A: B: C: D: E = 9: 12: 15: 30: 40
So, this is how we solve these types of questions quickly.
I will update one more session of this chapter regarding proportions.

6 comments:

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