On a test consisting of 250 questions, Jassi answered 40% of the first 125 questions correctly. What percent of the other 125 questions does she need to answer correctly for her grade on the entire exam to be 60% ?

Answer: Option C

Number of questions answered correctly :
= 40% of 125
= 50
For 60% grade, number of questions to be answered correctly :
= 60% of 250
= 150
Remaining number of question to be answered correctly :
= 150 - 50
= 100
∴ Required percentage :
= $$\left(\frac{100}{125}\times 100\right)\%$$
= 80%