3
Q:

# 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

Q:

45% of 750  -  25% of 480 = ?

 A) 337.50 B) 217.50 C) 376.21 D) 120

Explanation:

Given expression = ($\inline \fn_jvn \small \frac{45}{100}$  x 750) - ($\inline \fn_jvn \small \frac{25}{100}$  x 480) = (337.50 - 120) = 217.50

1 4
Q:

What percent is 120 of 85 ?

 A) 133.33 % B) 141.17 % C) 145.54 % D) 139.29 %

Explanation:

$\fn_jvn \small \frac{Px85}{100}=120$

=> p = 12000/85 = 141.17 %

1 31
Q:

A number increased by 30% gives 390. The number is

 A) 180 B) 300 C) 480 D) 260

Explanation:

Let the number be 'N'
Given N + 30N/100 = 390
=> 130N/100 = 390
=> N = 390 x 10/13
=> N = 300.

1 32
Q:

If 25% of a number is subtracted from a second number, the second number reduces to its four-sixth. What is the ratio of the first number to the second number  ?

 A) 4:3 B) 2:3 C) 3:2 D) 5:3

Explanation:

Let the numbers be p & q

q-p/4 = 4q/6

=> q-4q/6 = p/4

=> 2q/6 = p/4

=> p/q = 4/3

2 56
Q:

A number, when 35 is subtracted from it, reduces to its 80 percent. What is four - fifth of that number  ?

 A) 175 B) 140 C) 135 D) 95