Problems based on Numbers Test 6

Saurabh needs to answer correctly to score 60% over all
Total number of correct question to get 60% is 60% of 150.
$=\frac{60}{100}\times 150=90$ questions
Saurabh answered 80% of the first 75 questions correctly
So, 80% of 75 will be:
$\frac{80\times 75}{100}=60$questions
He need 30 questions correct to get 60% marks overall out of 75 questions
Let x be the per cent.
Now, x % of 75 = 30
$\frac{\mathit{x}}{100}\times 75=30$
$\mathit{x}=\frac{30\times 100}{75}$
$\mathit{x}=40\%$
He had to answer correctly 40% of the other 75 questions.