Question

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

25 + 21 ÷ 3 - 35 × 5 = 81

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

Answer 1

Answer:

B. ÷ and ×

Interchanging the signs :- 25 + 21 ÷ 3 - 35 × 5 = 81 We have using BODMAS rules, Option 1) → + and - 25 - 21 ÷ 3 + 35 × 5 = 81 25 - 7 + 35 × 5 = 81 25 - 7 + 175 = 81 200 - 7 = 81 293 ≠ 81 Option 2) → ÷ and × 25 + 21 × 3 - 35 ÷ 5 = 81 25 + 21 × 3 - 7 = 81 25 + 63 - 7 = 81 88 - 7 = 81 81 = 81 Option 3) → + and × 25 × 21 ÷ 3 - 35 + 5 = 81 25 × 7 - 35 + 5 = 81 175 - 35 + 5 = 81 180 - 35 = 81 145 ≠ 81 Option 3) → × and - 25 + 21 ÷ 3 × 35 - 5 = 81 25 + 7 × 35 - 5 = 81 25 + 245 - 5 = 81 270 - 5 = 81 265 ≠ 81 Hence, "Option (B)" is the correct answer.