Question

A jar of cookie is the is 630g when 1/2 full(including the jars weight) and 855g when 7/9 full.

what is the mass of the empty jar?

how do i solve it?

Answer 1

\[630=1/2 \]
\[855=7/9\]
So u can find the ration of that by subtiact the ratio of 7/9 with 1/2 and 855 with 630, that's is \[850-630x=5/18\]
Solve that You will get 225g for each 5/18
each1/18 is equal 45g so, multiple by 18, so that's how much a jar can hold
that's equal 810

Answer 2

let jars weight be x
and total volume of jar be y
now equation
y1/2+x=630
7/9y+x=855
sove the two equation by substitution method