Answer:
To find the answer we only need to know,
Total no.of girls and Total no.of right handed girls.
So,
Total no.of right handed girls = 7/8
Total no.of girls = 8/8 (as given in question)
Total no.of left handed girls is,
(Fraction of total no.of girls) - (Fraction of total no.of left handed girls)
= 8/8 - 7/8
= 1/8
∴ 1/8 of the girls in the school are left handed.