Four friends--let's call them A, B, C, and D--are planning to go to the concert, but they realize that they are a few dollars short to buy the tickets ($50 per ticket).
We know that each of them has an integer amount of dollars and that
if borrowed $ from , then would have of 's balance;
if borrowed $ from , then would have of 's balance;
if borrowed $ from , then would have of 's balance.
At least how much more money (in $) do they need all together in order to afford 4 tickets?