Question

N a school of 2100 students, the ratio of teachers to students is 1:14. some teachers join the school and the ratio changes to 2:21.find the number of teachers who joined the school.

Answer 1

50 teachers joined the school.

Step-by-step explanation:

The ratio of teachers to students = 1 : 14

So the number of teachers be 'x' and students be '14x'

according to the given statement number of students = 2100

Therefore, 14x = 2100

                   $x=\frac{2100}{14}$

                   x = 150

The number of teachers who join the school = y and the ratio = 2 : 21

$\frac{150+y}{2100}=\frac{2}{21}$

3150 + 21y = 4200

21y = 4200 - 3150

21y = 1050

$y=\frac{1050}{21}$

y = 50

50 teachers joined the school.

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Answer 2

Answer:

50

Step-by-step explanation:

Let teacher be x

A/q

x/2100=1/14

x=2100/14

=150

Teacher =150

Case 2

Let increased no. of teacher be 150+m

A/q

150+m/2100=2/21

=150+m=(2100*2)/21

=150+m=200

=m=200-150

Therefore m=50

Hence the number of teachers joined=50.