Determine the number that must be subtracted from both terms of the ratio 43 : 91 to make the ratio 3 : 7.
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e. 7.
Let the number to be subtracted be x.
Then: (43 – x) / (91 – x) = 3 / 7
Cross-multiply: 7(43 – x) = 3(91 – x)
301 – 7x = 273 – 3x
301 – 273 = 7x – 3x
28 = 4x
x = 7