SSC CGL 2020: Quantitative Aptitude

**SSC CGL new vacancy 2020 has been out.**

One of the most scoring topics for** ****SSC CGL 2020** is quantitative aptitude.

Mock test in Hindi can also help you to practice more and score well.

Percentage (%) is a fraction or ratio where denominator is 100.

1.** n% of x means**

**( x * n)/100**

**Example**: 20% of 150 is (20*150)/100 =30

2. **n% of x= x% of n**

**Example**: 20% of 5= 5% of 20

(5*20)/100= (20*5)/100=1

3. find what percentage of **x** is **n**

**(n / x)*100**

4. If **x** is increased/decreased by **n**, then percentage

**x (1+ n/100)**

5. Percentage change in **value= (change/initial value)*100**

6. If price of a commodity increased/decreased by** N%**, then

change in consumption without changing the expenditure

will be:

**(N/ (100 + N)) * 100 %**

7. If the Population (P) is increasing with rate R% annually

then,

Population after **n** years =** P*(1 + R/100) n**

Population before **n** years = **P/ (1 + R/100 ) n**

8. If price** (P) **of a commodity depreciates **R%** annually then,

Price of commodity after **n** years = **P*(1 - R/100) n**

Price of commodity** n** years ago = **P/ (1 - R/100) n**

**SSC CGL 2020****: Ratio and Proportion**

**Ratio(x/y)** is the relation between two or more values of same

kind. Where **x** is antecedent and **y** is consequent.

- In ratio order is important. For example:
** x: y** is not same

as **y: x**.

- If same number is multiplied or divided in each term of

ratio, then ratio will remain unchanged.

- Proportion
**(::)** is when ratio of first and second element is equal

to third and fourth element.

**A: B= C: D**

For example: **4:10:: 8: 20=2/5**

- Fourth Proportional
** (D) = (B*C)/ A**

- If second term is equal to third term
**A: B:: B:C** then,

Third proportional **(C) = B 2 /A**

- Mean proportional between
**A** and **B= âˆšAB** - Duplicate ratio of
** A **and **B = A 2 : B 2**

**SSC CGL 2020****: Speed, Distance & amp; Time**

**Measurements:**

Speed in km/hr or m/sec or miles/ hr.

Distance in Km or meter or miles.

Time is in hours or minutes or seconds.

Conversions:

**Km/hr to meter/ sec = speed in km/hr* 5/18**

**Meter/sec to km/hr= speed in m/sec* 18/5**

Formulas:

1. **Distance= Speed X Time**

**2. Speed=Distance/Time**

**3. Time= Distance/ Speed**

**4. If object is moving with x and y speed, then**

**Average speed = (2xy)/(x + y)**

5. When two objects are moving in same direction with** x** and

**y **speed then

**Relative speed = difference of x and y**

6. When two objects are moving in different direction with **x**

and** y**.

then,

**Relative speed= addition of x and y**

7. If time taken by objects is same, then

**Average speed= (x + y)/2**

8. If distance covered by objects is same, then

**Average speed= 2x*y/ (x + y)**

9. If two people moving between two points A and Bin

opposite direction by crossing each other, then speed of

them will be:

**Speed of A/ Speed of B=âˆšTime taken by B/ Time taken by A**

10. Calculation of least time taken to meet in circular race

is** LCM (T1, T2, T3â€¦â€¦ Tn**) i.e. Least common Multiple.