Question

the average age of a class of 10 students is 18 years. if the teacher,s age is included the new average becomss 22. what is the teacher,s age??​

Answer 1

Total = number of persons * average

18*10=180

Includes teacher

22*11= 242

Age of teacher = 242 - 180 = 62

Step-by-step explanation:

Answer 2

❏ Solution :-

The average age of 10 students is = 18 years.

∴ Total age of 10 students

=(18×10 ) years

= 180 years.

According to the question if sir's age is added to this , the average age becomes = 22 years.

Now, let the age of sir is = X years .

✏ Total age now = ( 180 + X ) years.

Hence , the average age of (10+1)= 11 people is 22 years

So now arranging this in the form of algebraic equation , we get :

$\implies\sf{\ \ {\dfrac{180+X}{11}=22}}$

$\implies\sf{\ \ {180+X=22\times11}}$

$\implies\sf{\ \ {X=242-180}}$

$\implies\large{\boxed{\sf{\ \ {X=62}}}}$

∴ Age of Sir is = 62 Yrs.

$\setlength{\unitlength}{1.0 cm}}\begin{picture}(12,4)\thicklines\put(1,1){\line(1,0){6.5}}\put(1,1.1){\line(1,0){6.5}}\put(1,1.2){\line(1,0){6.5}}\end{picture}$

$\setlength{\unitlength}{1.0 cm}}\begin{picture}(12,4)\thicklines\put(1,1){\line(1,0){6.5}}\put(1,1.1){\line(1,0){6.5}}\end{picture}$

$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\bf{\blue{\underline{\underline{\ \ {\bf{\red{COVID-19}}}}}}}$

$\setlength{\unitlength}{0.11cm}}\begin{picture}(12,4)\thicklines\put(-10,9){\line(6,5){11}}\put(-11.4,9){\line(6,5){12.5}}\put(-10,9.0){\line(-1,0){1.4}}\put(12,9){\line(-6,5){5.3}}\put(13.4,9.0){\line(-6,5){5.4}}\put(13.4,8.9){\line(-1,0){1.5}}\put(5.8,14.1){\line(-6,5){4.8}}\put(4.5,16.55){\line(-6,5){3.5}}\qbezier(1,10)(-10,15)(1,1)\qbezier(1,10)(10,15)(1,1)\put(4.5,16.47){\line(0,1){2}}\put(5.75,14.){\line(0,1){3}}\put(6.6,13.3){\line(0,1){3.7}}\put(8,13.5){\line(0,1){5}}\put(4.5,18.5){\line(1,0){3.6}}\put(6.7,16.9){\line(-1,0){1}}\put(7,3){ \#StayHome }\put(9.5,0){ StayHomeSaveLives.us }\end{picture}$

$\setlength{\unitlength}{1.0 cm}}\begin{picture}(12,4)\thicklines\put(1,1){\line(1,0){6.5}}\put(1,1.1){\line(1,0){6.5}}\end{picture}$