**Quantitative Aptitude Tricks PDF**:- **Quantitative Aptitude Tricks** are very important to crack any competitive exam. They help save your time during the exam that will help you improve your chances of selection. Quantitative Aptitude section is asked in almost every competitive exam including IBPS, SSC, Railways and more.Below are some tips provided to help you solve quantitative aptitude problems quickly. Go through them to accelerate your speed of preparation. In this blog we provide you a number of Quantative Aptitude Tricks. A number of tricks are given below to help you understand them:-

**Contents**hide

## Quantitative Aptitude **Cube Root:**

**Cube Root of 19683:**

⇒ Here the one’s digit is having 3, so we will find cube of which numbers from 1 to 9 are having 3 in the ones digit place which will be 7. So 7 will form the one’s digit of the cube root of 19683.

⇒ Now 19 falls between the cube of 2 and 3, so the smaller number between 2 and 3 i.e. 2 will form the tens digit of the cube root.

⇒ Hence, the cube root of 19683 will be 27.

**Multiplication with 5**

Simply multiply the number by 10 and then divide it by 2.

For example 99×5= 990/2= 495

**Multiplication with 99**

Multiply the number with 100 and then minus the same number from the result. Let’s take an example

Multiply 32×99 = 3200 – 32 = 3168

**Number Series**

In Number series questions, you need to find the pattern of series.

Let’s take an example : **16, 26, 6, 46, -34, ?**

There is a pattern in the difference between the numbers in the series.

Every consecutive difference is **multiplied by -2.**

**Conversion of km/hr into meter/sec**

Following formula is used in this case

**Conversion of meter/sec into km/h **

The formula is:

### Boats & Stream Tricks with Questions

**Upstream: **When the boat (or swimmer) moves against i.e. in the opposite direction of the stream.**Downstream: **when the boat (or swimmer) moves in the same direction as that of the stream.

Now, if the speed of the boat is B km/hr while the speed of the stream is S km/hr, then

Upstream speed U = (B – S) km/hr

Downstream speed D = (B + S) km/hr

If in the question, you are provided with the upstream and the downstream speed U and D respectively, to determine the speed of boat and stream the formula goes like

Speed of boat B = (D + U) / 2

Speed of stream S = (D – U) / 2

**Question: ****In still water, the speed of the boat is 7 km/hr. Find out the downstream speed of a boat in the river whose speed of the stream is 2 km/hr.**

Solution: Downstream speed = Speed in still water + Speed of stream = 7 + 2 = 9 km/hr

A couple more formulae,

**Question: In still water speed of boat is 8 km/hr. Find the upstream speed of boat which is floating in the sea where speed of waves is 3 km/hr.****Solution: **Speed of the boat (B) = 8

Speed of the stream (S) = 3

Upstream speed = B – S = 8 – 3 = 5 km/hr (answer)

**Question:The speed of a boat in downstream is 24km/hr and speed of the stream is 8 km/hr. find the speed of the boat in still water.****Solution:** Downstream speed = 24

Speed of the stream (S) = 8

According to the formula,

Downstream = B + S

24 = B + 8

Speed of the Boat (B) = 24 – 8 = 16 km/hr (answer)

**Playing with Percentages**

**Technique 1 **

If out of the total apples 60% are bad, i.e., 100% – 60% = 40% is good.

So, when we are asked the number of good apples, simply do the mental calc (short form of calculation!) and get the figure of 40%, the multiply with the total number of apples say 600, which is :40 x 600 / 100 = 240 apples**Technique 2**

You already know that the ‘00s in 600 and ‘00s in 100 get cancelled, then why waste time writing down the entire figure?

Simply multiply 40 x 6 = 240!

**Alligation and Mixture : Tricks**

**Ques 1. Gold is 19 times as heavy as water and copper 9 times. In what ratio should these materials be mixed so that the mixture may be 15 times as heavy as water.**Solution:-

**Ques2.How much chicory at Rs. 4 a kg should be added to 15 kg. of teat Rs 10 a kg. so that the mixture be worth Rs. 6.50 a kg?**Solution:-

**Ques 4.A sum of Rs. 6.40 is made up of 80 coins which are either 10-paise or five-paise coins. How many are of 5-p.?**Solution:-

**Ques 5.In a zoo, there are rabbits and pigeon. If heads are counted, there are 200 and if legs are counted, there are 580. How many pigeons are there?**Solution:-

**Mixture**

Questions related to mixtures can be easily solved by alligation method. By using alligation we can wide arrange of maths questions. Let me explain this with a simple example**Example: The price of wine of $60 per litre. If Samuel is adding water with and selling the mixture for $40 per litre. Profit margin remains same. What is the ratio of water and wine in the mixture?**

**Profit and Loss**

**Profit/loss = Sales price – Cost price****In case of profit **

25% of Cost Price (1/4 of CP) = 20% of Selling Price (1/5 of SP)

Similarly, 1/3 of CP = 1/2 of SP**In case of loss**

25% of Selling Price (1/4 of SP) = 20% of Cost Price (1/5 of CP)

Similarly, 1/3 of SP = 1/2 of CP

**Time and Work**

Every question in time and work chapter can be solved easily by finding the efficiency of workers or subject (such as pipes).**For example** – A takes 10 days to complete a job. B takes 20 days to complete the same job. In how many days they will complete the job if they work together?

⇒ A’s efficiency = 100/10 = 10% per day

⇒ B’s efficiency = 100/20 = 5% per days

⇒ A and B can do 15% of the work in a day if they work together. So they can do the whole job in 100/15 = 6.66 days or 6 days and 18 hours.

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