2

# 600 students took the test on physics and chemistry. 35% students failed in physics and 45% students failed in chemistry and 40% of those who passed in chemistry also passed in physics, then how many students failed in both:

 A) 162 B) 138 C) 60 D) None of these

Explanation:

Physics             Chemistry

Failed           35%                    45%

Passed         65%                    55%

Passed in both = 22% of total student

percentage of students who are passed in any of the physics or chemistry or both =(65+55) - 22 = 98%

So, the percentage of students who are failed in both = 2%

Therefore, total failed (in both subjects) students = 12

• Related Questions

The ratio of earnings of A and B is 4:5. If the earnings of A increase by 20% and the earnings of B decrease by 20%, the new ratio of their earnings becomes 6:5. What are A's earnings?

 A) Rs.22,000 B) Rs.27,500 C) Rs. 26,400 D) Cannot be determined

Explanation:

Subject: Percentage - Quantitative Aptitude - Arithmetic Ability
Exam Prep: Bank Exams
Job Role: Bank PO

52

If the length of a rectangle is increased by 10% and the area is unchanged , then its corresponding breadth must be decreased by?

Suppose length = 100m and breadth = x m

Area = 100 m

New length = 110m and breadth = (x-y% of x)

Then, $\inline&space;110\times&space;(x-\frac{y}{100}x)=100\times&space;x$

$\inline&space;\Rightarrow$ $\inline&space;110\times&space;(1-\frac{y}{100})=100$

$\inline&space;\Rightarrow$ $\inline&space;1-\frac{y}{100}=\frac{100}{110}$

$\inline&space;\Rightarrow&space;\frac{y}{100}=1-\frac{100}{110}=\frac{1}{11}$

$\inline&space;y=\frac{100}{11}=9\frac{1}{10}$%

Subject: Percentage - Quantitative Aptitude - Arithmetic Ability

43

The tax on an article decreases by 10% and its consumption increases by 10%. Find the effect percent on its revenue?

10 - 10 - $\inline&space;\frac{10\times&space;10}{100}=&space;-1%$ %

$\inline&space;\therefore$ Decrease in revenue = 1%

Subject: Percentage - Quantitative Aptitude - Arithmetic Ability

8

From a salary of an officer, 10% is deducted as house rent, 15% of the rest he spend on children's education and 10% of the balance he spends on clothes. Then, he is left with Rs. 4131. Find his total salary?

Suppose his total salary be Rs.x, then

90% of 85% of 90% of x = 4131

$\inline&space;\Rightarrow&space;\frac{90}{100}\times&space;\frac{85}{100}\times&space;\frac{90}{100}\times&space;x=4131$

$\inline&space;\therefore&space;x=\frac{4131\times&space;100\times&space;100\times&space;100}{90\times&space;85\times&space;90}=6000$

Hence , the salary of the officer is Rs.6000

Subject: Percentage - Quantitative Aptitude - Arithmetic Ability

12

In an election, there were two candidates only. The candidate who got 62% of the total votes polled and was elected by a majority of 192 votes. The total number of votes polled was?

Suppose total votes polled is x

$\inline&space;\Rightarrow$ $\inline&space;\frac{62x}{100}=\frac{38x}{100}+192$

$\inline&space;\Rightarrow&space;\frac{62x}{100}-\frac{38x}{100}=192$

$\inline&space;\Rightarrow&space;\frac{24x}{100}=192\Rightarrow&space;x=800$