The average questions

Question

The average salary of teachers of a school is Rs 3000. when salary of 2 more teachers is included, the average salary reduce by rs 100 and the total salary increased by rs 4000. now, find the numbers of teachers

Answer 1

Number of teachers = n

Total salary = x 

 

Average = x / n

 

3000 = x / n

 

x = 3000 n --------eq 1

 

when salary of 2 more teachers is included, the average salary reduce by rs 100 and the total salary increased by rs 4000

 

3000 -100 =( x + 4000) / (n + 2)

2900 = (x+4000)/(n+2)

2900(n+2) = (x+4000)

2900n +5800 = 3000n +4000  -----------from eq 1

 

100n =1800

n =18

 

so number of teachers =n= 18