The average score of 42 students in a test is 69. The ratio of the number of boys to that of girls is 10 : 11. The average score of the boys is 20% more than that of the girls. The average score of the boys is:

75.6

Ratio of No. of Boys to Girls = 10 : 11

20% = +\(\frac{1}{5}\)

Ratio of average score ⇒ Boys : Girls = 6 : 5

Now,

Accordingly average of all students = \(\frac{(6 × 10) + (5 × 11)}{10 + 11}\) = \(\frac{115}{21}\)

ATQ,

\(\frac{115}{21}\)R = 69

1R = 69 × \(\frac{21}{115}\)

Average score of Boys = 6R = 6 × 69 × \(\frac{21}{115}\) = 75.6