Question

A student has obtained 75%, 80%, and 85% in three subjects . If the marks of another subject is added then his average can not be less than

• A. $60\%$
• B. $65\%$
• C. $80\%$
• D. $90\%$

Answer 1

The correct option is A $60\%$

Marks obtained from $3$ subjects out of $300$

is $75+80+85=240$

If the marks of another subject are added

then

marks $\ge$ 240 out of 400 [min any]

$\Rightarrow \frac{240}{4}=60$ [ when marks is $4^{th}$ subject is $0$]

$\therefore$ $60\%$