MyQuestionIcon

1

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Proportion

Find the four...

Question

Find the fourth proportional.
15:20 :: 9:?

A

14

No worries! We‘ve got your back. Try BYJU‘S free classes today!

B

12

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

C

7

No worries! We‘ve got your back. Try BYJU‘S free classes today!

D

3

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is B 12
Let the fourth proportional be x.
$⟹$ 15, 20, 9 and x are proportional.
i.e., 15:20 :: 9:x
$15 \times x = 20 \times 9 (P r o d u c t o f e x t r e m e s = P r o d u c t o f m e a n s)$
$⟹$ x = $\frac{20 \times 9}{15}$
$⟹$ x = 12
Hence the fourth proportional is 12.

Suggest Corrections

thumbs-up

1

Similar questions

Q. Find the fourth proportional to

\frac{1}{15}, \frac{1}{5}, \frac{1}{12}

Q. Find out the fourth proportional to 4, 9, 12.

Q. Find the fourth proportion of

5, 7, 15

Q. If 60 is the fourth proportional to 8, 15 and x; find x.

Q. Find the fourth proportion for

1 \frac{5}{7}, 2 \frac{3}{14}, 3 \frac{3}{5}

View More

Join BYJU'S Learning Program

similar_icon

Related Videos

lock

Proportion

MATHEMATICS

Watch in App

explore_more_icon

Explore more

Standard VII Mathematics

Join BYJU'S Learning Program

CrossIcon