CONCEPT: The question is based on the concept of ratios

SOLUTION:
 

 Total share of Paul and Quallis together

 = 2+3=5 parts

and this is less than Robert's share by 7-5=2 part.


 These 2 parts = $1500


 =>1 parts = $750


Paul is 2 parts =2*750 = $1500 (OPTION C)