Answer to Question #334342 in Algebra for Ombiro

Question

the ratio of girls to boys in a school is 3:7. on a Monday, 1/4 of the girls were absent and 1/6 of the boys were absent. if 16 fewer learners had been absent, then 7/8 of the school would have been present. calculate the number of learners present at school that day

Answer 1

Let there be $N$ learners, $\frac{3}{10}N$ girls and $\frac{7}{10}N$ boys.

On Monday $\frac{1}{4}\cdot\frac{3}{10}N+\frac{1}{6}\cdot \frac{7}{10}N=\frac{23}{120}N$ learners were absent. And $\frac{97}{120}N$ learners were present.

We have that $\frac{23}{120}N-16=\frac{1}{8}N$

$\frac{1}{15}N=16$

$N=240$

$\frac{97}{120}N=194$

Answers: 194 learners.