Im notr sure but if we take the chances that the 4 sum has to be either (1.3) (3.1) (2.2) (2.2) that means its chance is 4/36 for each roll which is also 1/9 ,, we can multiply 1/9 times the roll times ( 252 ) we get =28
C= 5.5 I'm pretty sure that's the answer
d= 4.5 and c+ 5.5
Because 4.5 plus 1.0 = 5.5
since c is one more than d
5.5 plus 4.5 = 10