The ratio of the third proportion of 5 and 12 with the fourth proportion of 5, 8 and 9 is:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 2 : 1.
Let the third proportion of 5 and 12 be c
and the fourth proportion of 5, 8, and 9 be d
According to the question;
The third proportion of 5 and 12 is c = 122/5
⇒ c = 144/5
The fourth proportion of 5, 8, and 9 is d = (8 × 9)/5 = 72/5
Hence, the required ratio is (144/5) : (72/5) = 2 : 1