Question

In a college 45 % students are in Mathematics department, 30 % are in Physics department, 15 % are in

Biotechnology department and rest are in Chemistry department. If there are 120 students in chemistry

department, then find the total number of students in the college.​

Answer 1

Answer:

There are 1200 students in the college

Step-by-step explanation:

Given :

45% students in Mathematics department

30% students in Physics department

15% students in Biotechnology department

And 120 students in Chemistry department

To find :

Total number of students in the college

Taken :

To find the total number of students in the college use this formula -:

$\boxed{\sf{T=\dfrac{100\%}{100\%-(45\%+30\%+15\%)}\times120}}$

T = Total number of students in the college

Here , at denominator we have to find the percentage of students in Chemistry department.

Solution :

$\leadsto\sf{T=\dfrac{100\%}{100\%-(45\%+30\%+15\%)}\times120}$

$\leadsto\sf{T=\dfrac{100\%}{100\%-(75\%+15\%)}\times120}$

$\leadsto\sf{T=\dfrac{100\%}{100\%-90\%}\times120}$

$\leadsto\sf{T=\dfrac{100\%}{\cancel{10}\%}\times\cancel{120}}$

$\leadsto\sf{T=100\%\times12}$

$\leadsto\sf{T=1200\:students}$

So , the total number of students in the college is 1200 students.