Percentage
- The tax imposed on an article is decreased by 10% and its consumption increases by 10%. Find the percentage change in revenue from it.
-
View Hint View Answer Discuss in Forum
Using Rule 3
Tricky approach
Required change= (10)2 % decrease = 1% decrease 100 Correct Option: C
Using Rule 3
Tricky approach
Required change= (10)2 % decrease = 1% decrease 100
- A number is increased by 20% and then it is decreased by 10%. Find the net increase or decrease per cent.
-
View Hint View Answer Discuss in Forum
Using Rule 4,
Net % change= A + B + AB % 100
Here, A = 20%, B = – 10%
∴ Net % change20 - 10 - 200 100
= 10 – 2= 8%
+ ve sign shows increaseCorrect Option: C
Using Rule 4,
Net % change= A + B + AB % 100
Here, A = 20%, B = – 10%
∴ Net % change20 - 10 - 200 100
= 10 – 2= 8%
+ ve sign shows increase
- Salary of a person is first increased by 20%, then it is decreased by 20%. Percentage change in his salary is :
-
View Hint View Answer Discuss in Forum
Using Rule 4,
Change in his salary= 20 - 20 - 20 × 20 % 100 = - 400 % = – 4% 100
i.e. 4% decrease
Note : If A is first increased by x% and then decreased by y% the net % change= x - y - xy % 100
If the result is positive, the change indicates increase and if the result is negative, the change indicates decrease.Correct Option: A
Using Rule 4,
Change in his salary= 20 - 20 - 20 × 20 % 100 = - 400 % = – 4% 100
i.e. 4% decrease
Note : If A is first increased by x% and then decreased by y% the net % change= x - y - xy % 100
If the result is positive, the change indicates increase and if the result is negative, the change indicates decrease.
- An examiner has to secure 40% marks to pass an examination. He secures 180 marks and fails by an equal number of marks. The total number of marks in the examination is
-
View Hint View Answer Discuss in Forum
NA
Correct Option: A
NA
- An engineering student has to secure 25% marks to pass. He gets 47 and fails by 43 marks. What are the maximum marks of the examination ?
-
View Hint View Answer Discuss in Forum
Maximum marks of examination = x (let)
According to the question,
25% of x = 47 + 43= x × 25 = 90 100 ⇒ x = 90 ⇒ x = 4 × 90 = 360 4 Correct Option: C
Maximum marks of examination = x (let)
According to the question,
25% of x = 47 + 43= x × 25 = 90 100 ⇒ x = 90 ⇒ x = 4 × 90 = 360 4