Question

Arun scored $36$ marks in English, $44$ marks in Hindi, $75$ marks mathematics and $x$ marks in science. If he has secured an average of $50$ marks, find the value of $x$.

Answer 1

Given average $=150$,

Average or Mean $=$ Sum of the observations $÷$ No. of observations,

No. of observations is $4$

Marks in English $=36$,
Marks in Hindi $=44$,
Marks in Maths $=75$,
Marks in science $=x$,

Now , Let us find sum of observations ,

$=36+44+75+x=(155+x)$,

Substituting all the values in the above formula,

$\Rightarrow \frac{(155+x)}{4}=50$,
$\Rightarrow 155+x=200$
$\Rightarrow x=45$

So therefore he got $45$, marks in science,