Question 1140049
.
<pre>

The ratio  {{{House_blend/Rift_Valley_blend}}}  is the same and must remain the same.


So, the proportion is  {{{50/20}}} = {{{20/R}}},  where R is unknown amount of the Rift Valley blend, in pounds.


From the proportion,  R = {{{(20*20)/50}}} = {{{400/50}}} = 8 pounds.    <U>ANSWER</U>
</pre>

Solved.