Question

The two numbers whose mean proportional is 14 and third proportional is 4802 are:

• A. 8 and 24
• B. 2 and 98
• C. 7 and 28
• D. 4 and 49

Answer 1

Answer:

B. 2 and 98

Solution: Calculation Let the numbers be x and y, Mean proportional = √xy = 14 ⇒ xy = 196 ---- (1) Third proportional = y2/x = 4802 ⇒ y2 = 4802x ---- (2) Putting the value of x from this in 1st equation, ⇒ y3/196 = 4802 ⇒ y3 = 4802 × 196 ⇒ y3 = 98 × 98 × 98 ⇒ y = 98 ⇒ y = 98 and x = 196/98 = 2 ∴ The two numbers are 2 and 98.