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Two important Tips for Competitive Exam

These two tips are always use for easy calculation to save extra time. In competitive exam mostly questions are basic calculation type, but time allotted is very little. One main reason of failing in competitive exam is bad time management. So we need some basic time saving tips to save extra time.These two tips are given below in details,

Imperfect square estimation:

We have already discussed about square root of perfect square. In this chapter we estimate the square root of imperfect squares with the help of perfect square. We can easily find the square root of imperfect squares with the help of calculator. But in most competitive exam calculator is not allowed.

Let we need to find the square root of 60.
So to estimate square root of 60 we must go through some steps. These steps are,

  • First we have to find the perfect square root less than 60. We get 49 is the perfect square root less than 60. Perfect square of 7 is 49.
  • Now we divide 60 by this 7 and will get 8.57.
  • Now take average of the two numbers 7 and 8.57. And average of the two number is 7.76(take only 2 decimal places). So square root of 60 is 7.76.

Find square root of 43. So steps are,

  • First find perfect square root less than 43. We find 36 as the perfect squares of 6.
  • Now divide 43 by 6 and get 7.17.
  • Now take average of 6 and 7.17. So average of these two numbers are 6.56(up to 2 decimal places only). So square root of 43 is 6.56.

Percentages partition:

I always use this method to solve question about percentage finding. Mainly we need to find percentage in Data Interpretation problem which consist graph, chart etc.
Why it is called Percentage Partition method?
In this method we find percentage part by part. This method can be understood with an example.
1) Find 134% of 2556?
Here we can write (100 + 3×10 + 4×1) % of 2556.
So,
100% of 2556 = 255610

10% of 2556 = 255.6
1% of 2556 = 25.56
So,
(3×10) % = 30% of 2556 = (3×255.6) = 766.8
(4×1) % =4% of 2556 = (4×25.56) = 102.24
So 134% of 2556 = (2556 + 766.8 + 102.24) = 3425.04
2) Find 65% of 3456?
Here we can write [(100/2) + 10 + (10/2)] % of 3456.
So,
100% of 3456 = 3456
(100/2)% = 50% of 3456 = (3456/2) = 1728
10% of 3456 = 345.6
(10/2)% = 5% of 3456 = (345.6/2) = 172.8
So 65% of 3456 = (1728 + 345.6 + 172.8) = 2246.4