A.).
50 + 10 / 5 + 5 ============> 50 + 1 =====> 51
50 + 10 / 10
Answer: Letter Choice, (A), 50 + 1 ====> 51
B.).
50 + 10 / 5 + 5
50 + 2 + 5
Answer: 50 + 7 ======> 57
C.).
( 50 + 10 ) / 5 + 5
50 + 10 / 5 + 5
60 / 5 + 5
Answer: 60 / 10 ======> 6
D.).
( 50 + 10 ) / 5 + 5
50 + 10 / 5 + 5
60 / 5
Answer: 12 + 5 =======> 17
Therefore; Letter Choice; ( A), Answer: 50 + 10 / 5 + 5 ============> 50 + 1 =====> 51
Hope that helps!!!! : )