Find out the two signs to be interchanged to make the following equation correct.
18 + 3 × 27 − 9 ÷ 3 = 78
- A+ and ×
- B+ and ÷
- C– and ÷
- D+ and -
Solution & Step-by-step Explanation
Let us check option D by interchanging the signs + and −:
The original equation becomes:
18−3×27+9÷3
Applying BODMAS rule:
Division: 9÷3=3
Multiplication: 3×27=81
Substitution into equation: 18−81+3
Addition and Subtraction: 18+3−81=21−81=−60
=78
Let us check option A by interchanging + and ×:
The equation becomes:
18×3+27−9÷3
Division: 9÷3=3
Multiplication: 18×3=54
Addition and Subtraction: 54+27−3=81−3=78
Since LHS = RHS = 78, interchanging + and × makes the equation correct.
The original equation becomes:
18−3×27+9÷3
Applying BODMAS rule:
Division: 9÷3=3
Multiplication: 3×27=81
Substitution into equation: 18−81+3
Addition and Subtraction: 18+3−81=21−81=−60
=78
Let us check option A by interchanging + and ×:
The equation becomes:
18×3+27−9÷3
Division: 9÷3=3
Multiplication: 18×3=54
Addition and Subtraction: 54+27−3=81−3=78
Since LHS = RHS = 78, interchanging + and × makes the equation correct.