Answer:
Option B
Explanation:
Total marks $= 50$% of$ 50 + 60$% of $50 + 70$% of $50 +70$% of 50
$=\frac{\left(50\times 50\right)}{100}$ $+ \frac{\left(60\times 50\right)}{100}$ $+ \frac{\left(70\times 50\right)}{100}$ $+\frac{\left(70\times 50\right)}{100}$
$=125$