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I came to correct the numbers in the solution by @greenestamps
The given information compares the amounts that both Maria and Betsy receive to the amount John receives.
So make the amount John receives your variable.
x = amount John receives
2x = amount Maria receives (twice as much as John)
3x = amount Betsy receives (three times as much as John)
The total was $3750:
x + 2x + 3x = 3750
6x = 3750
x = 3750/6 = 625.
ANSWER. John receives $625; Maria receives $1250; Betsy receives $1875.
CHECK. $625 + $1250 + $1875 = $3750, in total. ! Correct !