Question 1011052
7. William fills 1/3 of a water bottle in 5/9 of a
minute. How many bottles can he fill in a
minute?   Please explain this to me so I can explain it to my grandaughter who is in 7th grade, but special education student.  Thanks
<pre>The easiest way to explain this is with proportions. We can say that:
{{{(number_of_water_bottles)/(amount_of_minutes) = ( number_of_water_bottles)/(amount_of_minutes)}}}
{{{(1/3)/(5/9) = N/1}}} ------- Substituting {{{1/3}}} & N (this is what's required) for number of water bottles, and {{{5/9}}}, & 1 for amount of minutes
Since this is a proportion (fraction on either side of the equals sign), we can cross-multiply. This results in:
{{{(5/9) * N = (1/3) * 1}}}
{{{5N/9 = 1/3}}}
3(5N) = 9 ------- Cross-multiply, again
15N = 9
N, or number of water bottles = {{{9/15}}}, or {{{highlight_green(3/5)}}} of a water bottle