Question

Which two signs should be interchanged to make the given equation correct?

$28 - 28 \div 14 + 7 \times 2 = 16$

• A. x and -
• B. + and ÷
• C. x and ÷
• D. + and -

Answer 1

Answer:

D. + and -

To make the given equation correct, the two signs that should be interchanged are $-$ and $+$.

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The original given equation is:
$28 - 28 \div 14 + 7 \times 2 = 16$

Let's interchange the minus sign ($-$) and the plus sign ($+$):
$28 + 28 \div 14 - 7 \times 2 = 16$

Now, we solve the left-hand side (LHS) using the BODMAS rule:

1. Division ($\div$):
   $28 \div 14 = 2$
   The equation becomes: $28 + 2 - 7 \times 2$

2. Multiplication ($\times$):
   $7 \times 2 = 14$
   The equation becomes: $28 + 2 - 14$

3. Addition ($+$) and Subtraction ($-$):
   $28 + 2 = 30$
   $30 - 14 = 16$

Since LHS = RHS ($16 = 16$), interchanging $-$ and $+$ is the correct answer.