The average pass percentage of girls in class X examination in a school is 85% and that of boys is 83%. The average pass percentage of all boys and girls in class X of that school is 83.7%. Find the percentage of the number of girls in class X of that school.

35%

By using Allegation Method ,

Percentage of Girls in class X =  \(\frac{7}{20}\) × 100

= 35%