Choice A is incorrect
50+(10÷5+5)
50+ (2+5)
50+7
57
__________
Choice B is incorrect.
(50 + 10) ÷ (5 + 5)
60 ÷ 10
6
__________
Choice C is correct.
50 + 10 ÷ (5 + 5)
50 + (10 ÷ 10)
50 + 1
51
__________
Choice D is incorrect.
(50 + 10) ÷ 5 + 5
(60 ÷ 5) + 5
30 + 5
35
