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Maths Puzzle
Numerical Ability
The average age of 30 students in a class is 9 years.If the teacher's age includes an average of 10 years then what is the teacher's age
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- no. of person = 30
average age = 9
then total age = 30*9 = 270...............(previous total age)
after including teacher no. of person = 31
average age = 10
then total age = 31*10 = 310..............(new total age)
difference = 310-270 = 30...ans.
the age of teacher = 30 year. - 10 years agoHelpfull: Yes(0) No(3)
- x/30=9
then x= 270
y is the age of teacher
(x+y)/31=10
(270+y)=310
so,
y=40 ans... - 10 years agoHelpfull: Yes(0) No(0)
- sorry
ans. is 40 year. - 10 years agoHelpfull: Yes(0) No(0)
- 40 Years...
- 10 years agoHelpfull: Yes(0) No(0)
- sum of ages of students= 30*9 = 270
let teacher's age be x
x+270=31*10
x=310-270=40
therefore, teacher's age is 40 - 10 years agoHelpfull: Yes(0) No(0)
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