Which two signs, from the given options, should be interchanged to make the given equation correct?
210 ÷ 7 × 320 ÷ (16 − 4 × 15 × 17) = 15 + 5
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. × and −.
Given equation: 210 ÷ 7 × 320 ÷ (16 − 4 × 15 × 17) = 15 + 5
Option 1: × and −
After interchanging the expression becomes:
= 210 ÷ 7 - 320 ÷ (16 × 4 - 15 - 17) = 15 + 5
= 210 ÷ 7 - 320 ÷ (64 - 15 - 17)
= 210 ÷ 7 - 320 ÷ 32
= 30 - 10
= 20 = 20
As we have found our answer, there is no need to check further options.
Hence, × and − is the correct answer.