# Shortcut Rules to Solve Problems on Percentage

### Effective for IBPS PO - SBI PO Exam

**Dear Reader,**

Here we will start a series of Quantitative Aptitude Shortcut Tricks for your upcoming SBI - IBPS - SSC and Other Government Competitive Exams. We will try to cover up all topics of the quantitative Aptitude Sections from which question was generally asked.

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**Trick – 1**

- If three successive discounts of x%, y% and z% are allowed on an amount then a single discount that equivalent to the three successive discounts will be

$\left[ x+y+z=\frac{xy+yz+zx}{100}+\frac{xyz}{{{100}^{2}}}
\right]%$

**Trick – 2**

- If X litres of oil was poured into a tank and its was still x % empty. Then the capacity of tank is

$\frac{X\times 100}{100-X}litres$

**Trick – 3**

- To split a number N into two parts such that one part is p% of the other.

The two split parts are $\frac{100}{100+p}\times N$ and $\frac{p}{100+p}\times N.$

**Trick - 4**

- In ‘A’ litres of x% acidic, liquid, the amount of water to be added to make y% acidic liquid is

$\frac{A\left( x-y \right)}{y}litres$

**Trick - 5**

- In a recent survey , x% houses contained two or more people. Of those houses containing only one person y% were having only a male. The percentage of all houses which contain exactly one female and no males is given by

$\left[ \frac{\left( 100-x \right)\left( 100-y \right)}{100} \right]%$

**Trick -6**

- If one of the sides of a rectangle is decreased by x% and the other is decreased by y%, then the percent value by which area changes is given by

$\left[ x+y-\frac{xy}{100} \right]%decrease$

**Questions for Practice****Q1. Find the discount equivalent to a discount series of 20%, 10% and 5%.**

**Q.2 240 litres of oil was poured into a tank and its was still 20 % empty. Find the capacity of tank.**

**Q3. Split the number 120 into two parts such that one part is 20% of the other.**

**Q4. What quantity the water should be added to reduce 9 litres of 50% acidic liquid to 30% acidic liquid ?**

**Q5. In a recent survey , 25% houses contained two or more people. Of those houses containing only one person 20% were having only a male. What is the percentage of all houses which contain exactly one female and no males ?**

**Q6. In measuring sides of a rectangle, one side is taken 5% in deficit and the other 4% in deficit. Find the error percent in area calculated from the measurement.**

__Answers__**Answer 1. 31.6%**

**Answer 2. 300 litres**

**Answer 3. 100 and 20**

**Answer 4. 6 litres**

**Answer 5. 60%**

**Answer 6. 8.8%**

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