Explanation:
here's your solution
=> total money received by them = $1600
=> the given ratio are 7:5:4
=> let the ratio be X ,now
=> Maria = 7X
=> Carolina = 5X
=> Pedro = 4X
=> we know whole money = $1600
=> so, adding all
=>. 7x + 5x + 4x = $1600
=> 16x = $1600
=> x= $1600/16
=>. x = $100
now Maria = 7*100 = $700
Carolina = 5*100 = $500
Pedro = 4*100 = $400
hope it helps