Which two numbers should be interchanged to make the given equation correct?
15 × 5 - 75 + (300 ÷ 6) + 3 × 19 = 115
(NOTE: Numbers must be interchanged and not the constituent digits e.g. if 2 and 3 are to be interchanged in the equation 43 × 3 + 4 ÷ 2, then interchanged equation is 43 × 2 + 4 ÷ 3)
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 15 and 19.
Given equation: 15 × 5 - 75 + (300 ÷ 6) + 3 × 19 = 115
After interchanging the numbers the equation becomes:
19 × 5 - 75 + (300 ÷ 6) + 3 × 15 = 115
⇒ (19 × 5) - 75 + 50 + (3 × 15) = 115
⇒ 95 - 75 + 50 + 45 = 115
⇒ 190 - 75 = 115