In a test, the average score of 50 students is 66. Out of the total students, 40% are girls and the rest are boys. The average score of the boys is 20% less than that of the girls. What is the average score of the girls?
Answer & explanation
Correct answer: option 3
Ratio of number of Girls to Boys = 2 : 3
Number of girls = \(\frac{50}{5}\) × 2 = 20
Number of Boys = \(\frac{50}{5}\) × 3 = 30
Ratio of average score of boys to girls = 4 : 5
20 × 5R + 30 × 4R = 50 × 66
100R+ 120R = 3300
220R = 3300
R = 15
Average score of Girls = 5R = 5 × 15 = 75