Question

the third proportional to 12 and 30.​

Answer 1

Answer:

Let the third proportional to 12 and 30 be x.

Then, 12 : 30 :: 30 : x

⇔ 12x = 30 × 30

⇔x=

12

(30×30)

=75

∴ Third proportional to 12 and 30 = 75.

Mean proportional between 9 and 25=

9×25

=15

∴ Required ratio = 75 : 15 = 5 : 1.