Answer:
676
Step-by-step explanation:
Let's first solve what 34% and 40% of 600 is.
[tex]0.34\cdot \:600 = 204[/tex]
[tex]0.4\cdot \:600 = 240[/tex]
So Anne buys 204 small packets and 240 large packets.
Likewise, we can apply the same thing for the next two people:
[tex]\frac{3}{10}\cdot \frac{400}{1} = 120[/tex]
[tex]\frac{1}{10}\cdot \frac{400}{1} = 40[/tex]
So Ben buys 120 small packets and 40 large packets.
[tex]210\: \div \:3 = 70[/tex]
[tex]70\:\cdot\:4 = 280[/tex]
So Chas buys 210 small packets and 280 medium packets.
We can add up the number of small packets and large packets and subtract them from the total to figure out the amount of medium:
[tex]204 + 240 = 444\\600 \:-\: 444 = 156[/tex]
156 medium packets for Anne.
[tex]120\:+\:40 = 160\\400 \:-\: 160 = 240[/tex]
240 medium packets for Ben.
And we already know that Chas has 280 medium packets.
[tex]156+240+280 = 676[/tex]
Thusly, the total number of medium packets of mints is [tex]\boxed{676}[/tex].
Hope this helps! ((:
