All Exams Test series for 1 year @ ₹349 only
Question

Which two signs should be interchanged to make the following equation correct? 
$56-74\times17+391\div23 = 1297$

The correct answer is
+ and -

Question Type: Arithmetic Reasoning

Step-by-step Solution:

The given equation is: \(56 - 74 \times 17 + 391 \div 23 = 1297\)

Let's evaluate the equation using the standard order of operations (BODMAS/PEMDAS):

  1. Division: \(391 \div 23 = 17\)
  2. Multiplication: \(74 \times 17 = 1258\)
  3. Subtraction and Addition: \(56 - 1258 + 17 = -1185\)

The result is -1185, which is not equal to 1297. We need to interchange two signs to make the equation correct.

Let's try interchanging the '+' and '-' signs:

\(56 + 74 \times 17 - 391 \div 23 = ?\)

  1. Division: \(391 \div 23 = 17\)
  2. Multiplication: \(74 \times 17 = 1258\)
  3. Addition and Subtraction: \(56 + 1258 - 17 = 1297\)

The equation now holds true: \(1297 = 1297\)

Why other options are incorrect:

  • Option 1 (\(\div\) and \(\times\)): Interchanging these would significantly alter the result and not lead to 1297.
  • Option 3 (\(\times\) and \(-)\): This would result in a large negative number.
  • Option 4 (\(\div\) and +): This would also result in a value far from 1297.

Core Logic/Pattern: The core logic is to systematically try interchanging the arithmetic operators to find a combination that satisfies the equation. The order of operations must be carefully followed.

Therefore, the correct answer is to interchange the '+' and '-' signs.

Was this answer helpful?

Important Questions from Bodmas Rule

  1. Solve: {7.88 × 2 + 2.4 × 5 - 242.4 ÷ 4 + [9.2 × 4 - 2.46 of 3 + (36.3 ÷ 3 - 1.42 × 2)]} 

  2. What will come in the place of question mark (?) in the given expression?

    (420 ÷ 12 × 35 + 452- 152) = ?2

  3. What will come in place of the question mark ‘?’ in the following question?

    (44 of 15) – [(450 × 240 ÷ 60 – 40) ÷ 80 × 25 + 50] – 10 = ?
  4. Simplify: 92 - 18 ( 9 + 36 ÷ 3 × 12 - 27 × 3) + 51

  5. Simplify the following expression.

    \(\rm \frac{3}{5}\ of\ \left\{\left(48\div\overline{36\div9}\times\frac{1}{6}\right)+\frac{1}{3}\right\}=?\)

Need Expert Advice?

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App