Question

The average marks of five subjects is reduced by 2 due to scoring 72 marks in
the sixth subject. What is the average marks of all the six subjects?​

Answer 1

Answer:

The average of all the six subjects is $\dfrac{5a+62}{6}$  

Step-by-step explanation:

Given as :

Let The average marks of first five subject = a

i.e average marks of five subjects = $\dfrac{a_1+a_2+a_3+a_4+a_5}{5}$

Or, a = $\dfrac{a_1+a_2+a_3+a_4+a_5}{5}$

Or, $a_1+a_2+a_3+a_4+a_5$  = 5 a

Again

The marks score in sixth subject = 72 marks

Let, The average marks of six subject = A

i.e A = $\dfrac{a_1+a_2+a_3+a_4+a_5+a_6}{6}$

Or, A = $\dfrac{a_1+a_2+a_3+a_4+a_5+72}{6}$

while scoring 72 marks in sixth subject, the average marks of five subject is reduced by 2

So, A = $\dfrac{5(a-2)+72}{6}$

Or, A = $\dfrac{5a+62}{6}$

Hence, The average of all the six subjects is $\dfrac{5a+62}{6}$ Answer