Last year, there were 610 boys in a school. The number decreased by 20% this year. How many girl are there in the school, if the number of boys in the school this year?

Last year number of boys in school = 610
∴ Number of boys in school this year = 610 - (610 x 20)/100
= 610 - 122 = 488
∴ Number of girls in school this year
= Number of boys in school this year x 175%
= (488 x 175)/100
= (488 x 7)/4
= 122 x 7
= 854
Hence, number of girls in school this year in 854.