Question

One third of the total number of students in a class are in chemistry laboratory,one fourth are in physics laboratory,one sixth are in biology laboratory and 12 are in maths lab . How many students are there in the class?

Answer 1

Let us consider the total no. of students as X.

So:
1/3 of x in chemistry laboratory,

1/4 of x in physics laboratory

1/6 of x in biology laboratory

And 12 in maths lab then
​​

1/3 of X + 1/4 of X + 1/6 of X + 12 = X (total students)

X/3 + X/4 + X/6 + 12 = X

4X + 3X + 2X + 144 / 12 = X

9X + 144 = 12X

9X - 12X = - 144

- 3X = - 144

X = 144/3 = 48 Nos.

Ans: 48 Students.