Pls help. Thanks

in 12 days they eat 1/4      six more days they eat  1/8

3 / 8 eaten leaves    5 /8   and this equals 21kg

5/8x = 21

x = 21 * 8/5 = _________ kg originally

Every 12 days, they ate $1 \over 4$ of the rice. 

This means that they ate $1 \over 8$ of the rice every 6 days. 

So, ${3 \over 4} - {1 \over 8} = {5 \over 8}$.

This means that ${5 \over 8} = 21$. By solving the ratios, we find that Jason originally had $\color{brown}\boxed{33.6}$ kg of rice.