Average age of A, B and C is 84 text{ years}. | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) The average age of $A, B$ and $C$ is $84 	ext{ years}$,so $A + B + C = 84 	imes 3 = 252$ ......$(1)$When $D$ joins,the average age of $A, B, C$

Vedclass · Accepted Answer

$80$

Vedclass · Answer

(A) The average age of $A, B$ and $C$ is $84 	ext{ years}$,so $A + B + C = 84 	imes 3 = 252$ ......$(1)$When $D$ joins,the average age of $A, B, C$ and $D$ becomes $80 	ext{ years}$,so $A + B + C + D = 80 	imes 4 = 320$ ......$(2)$Subtracting $(1)$ from $(2)$,we get $D = 320 - 252 = 68 	ext{ years}$.Given that $E$ is $4 	ext{ years}$ older than $D$,so $E = 68 + 4 = 72 	ext{ years}$.When $E$ replaces $A$,the new average of $B, C, D$ and $E$ is $78 	ext{ years}$,so $B + C + D + E = 78 	imes 4 = 312$.Substituting the values of $D$ and $E$,we get $B + C + 68 + 72 = 312$,which simplifies to $B + C + 140 = 312$,so $B + C = 172$ ......$(3)$Finally,substituting $(3)$ into $(1)$,we get $A + 172 = 252$,so $A = 252 - 172 = 80 	ext{ years}$.

Similar Questions

The average weight of $36$ students is $50 \,kg$. It was found later that the weight of one of the students was misread as $73 \,kg$,whereas his actual weight was $37 \,kg$. Find the correct average (in $kg$).

$A$ class has $20$ boys and $30$ girls. The average age of boys is $11$ years and that of girls is $12$ years. What is the average age of the whole class in years?

The average value of the numbers $15, 21, 32, 35, 46, x, 59, 65, 72$ should be greater than or equal to $43$ but less than or equal to $44$. Then the value of $x$ should be

$A$ batsman,in his $12^{th}$ innings,makes a score of $63$ runs and thereby increases his average score by $2.$ The average of his score after $12^{th}$ innings is

Vedclass Test Series

Exam Paper Generator

Online Exam Module