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Numerical Ability
Arithmetic
The present ratio of students to teachers at a certain school is 30 to 1. If the student enrollment were to increase by 50 students and the number of teachers were to increase by 5, the ratio of the teachers would then be 25 to 1 What is the present number of teachers?
Read Solution (Total 5)
-
- Present number of teachers = 15
Let X = Students
And Y = Teachers
Present ratio of students to teachers = 30:1
(i.e,)
X/Y = 30/1
X = 30Y --->(i)
If Student increase by 50 students and Teachers increase by 5 means,
Ratio = 25:1
(i.e,)
(X+50)/(Y+5) = 25/1
(X+50) = 25(Y+5)
--> (X+50) = 25Y+125
--> X = 25Y+125-50
--> X = 25Y+75 ==>(ii)
Substitute eqn (i) in eqn(ii). So,
30Y = 25Y+75
30Y-25Y = 75
5Y = 75
Y = 15.
So, present number of teachers = 15 - 12 years agoHelpfull: Yes(27) No(1)
- IF THE NO OF STUDENTS IS 30x,THEN NO OF TEACHERS IS x,
SO
(30x+50)/(x+5)=25/1
.
.
Or X=15 - 12 years agoHelpfull: Yes(12) No(2)
- IF THE NO OF STUDENTS IS 30k,THEN NO OF TEACHERS IS k,
SO
(30k+50)/(k+5)=25/1
k=15 - 10 years agoHelpfull: Yes(0) No(0)
- suppose X->student numbers
y- teacher numbers
X/Y = 30/1
X = 30Y --->(i)
After increase
(X+50)/(Y+5) = 25/1
(X+50) = 25(Y+5)
X = 25Y+75 ==>(ii)
Substitute eqn (i) in eqn(ii).
Y = 15. - 6 years agoHelpfull: Yes(0) No(0)
- 30:1 given
30x:x is ratio
30x+50/x+5=25/1 given
30x+50=25x+125
X=15 - 6 years agoHelpfull: Yes(0) No(0)
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