What is the value of a ? If 15 + 18 ÷ 3 × 5 - 12 ÷4 + a = 100

54 58 48 42

58

15 + 18 ÷ 3 × 5 - 12 ÷4 + a = 100  = 15 + 30 - 3 + a = 100 = 42 + a = 100 a = 58