Question

7. The average salary of the teachers
of a school was Rs. 3000. After the
appointment of two teachers, the
total salary increased by Rs. 4000
and the average salary decreased
by Rs. 100, then find the present
number of teacher​

Answer 1

Answer:

There would be 18 teachers

Step-by-step explanation:

Let x be the original number of teachers,

If average salary of the teachers = rs 3000,

Then total salary = number × average = 3000x,

After reducing the average salary by rs 100,

New average salary = 3000 - 100 = 2900,

If number of teachers is increased by 2,

New number of teachers = x + 2

So, total new salary = 2900(x+2)

According to the question,

2900(x+2) - 3000x = 4000

2900x + 5800 - 3000x = 4000

-100x + 5800 = 4000

-100x = 4000 - 5800

-100x = -1800

\implies x =\frac{-1800}{-100}=18⟹x=

−100

−1800

=18

Hence, there were 18 teachers.