Allow me to explain MMP
There's one mince and cheese pie left in the shop it costs $5
Bill has $4.50
Jacinda has $3.70
Winston has 70c
James has 60c
and David has 5c
No one has enough money to buy the pie by themselves but Jacinda, Winston and James put their money together and buy the pie. Bill gets no pie because he needed 50c but didn't have any friends to help him pay for the pie.
I hope this helps explain things.