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
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
(N/ (100 + N)) * 100 %
7. If the Population (P) is increasing with rate R% annually
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.
as y: x.
ratio, then ratio will remain unchanged.
to third and fourth element.
A: B= C: D
For example: 4:10:: 8: 20=2/5
Third proportional (C) = B 2 /A
SSC CGL 2020: Speed, Distance & amp; Time
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.
Km/hr to meter/ sec = speed in km/hr* 5/18
Meter/sec to km/hr= speed in m/sec* 18/5
1. Distance= Speed X 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
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=√Time taken by B/ Time taken by A
10. Calculation of least time taken to meet in circular race
is LCM (T1, T2, T3…… Tn) i.e. Least common Multiple.