Select the correct combination of mathematical signs that can sequentially replace the * signs and balance the given equation.
55 * 252 * 28 * 520 * 30 * 5
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → ×, ÷, =, –, +
Put the signs of an option in place of the * signs in order, and work out each side of ‘=’ by BODMAS. The option is right only when the two sides are equal.
With ×, ÷, =, –, + the equation reads 55 × 252 ÷ 28 = 520 – 30 + 5
Left side, multiplication and division from left to right: \(55\times252=13860\), then \(13860\div28=495\)
Right side, from left to right: \(520-30=490\), then \(490+5=495\)
Both sides are 495, so the equation is balanced
Why the other options are incorrect
Option (1) +, ÷, –, =, × — Incorrect. 55 + 252 ÷ 28 – 520 = 30 × 5 gives \(55+9-520=\) –456 on the left and 150 on the right.
Option (3) =, ×, +, ÷, – — Incorrect. 55 = 252 × 28 + 520 ÷ 30 – 5 gives more than 7000 on the right (252 × 28 alone is 7056), not 55.
Option (4) =, –, +, ÷, × — Incorrect. 55 = 252 – 28 + 520 ÷ 30 × 5 gives \(224+86\tfrac{2}{3}=\) 310\(\tfrac{2}{3}\) on the right, not 55.