[บาคุระ จัง]

boy 30 person worked somthing use times 4 1/2 hour
girl 50 person worked same somthing use times hour
if boy 15 person and girl 10 person worked onli 1 hour
Question . if boy 15 person and girl 10 person worked only 1 hour
it's only 1.6% of all work ?