Sainik School Entrance Exam 2020 Solved Paper

© examsiri.com

Question : 6 of 150

Marks: +1, -0

Three numbers are in the ratio

2: 3: 4

. The sum of their cubes is 33957 . The numbers are

16, 24 and 32
12,18 and 24
14, 21 and 28
18,27 and 36

Solution:

Suppose that, three numbers are

2 p, 3 p

and

4 p

Then,

(2 p)^3+(3 p)^3+(4 p)^3=33957

⇒8 p^3+27 p^3+64 p^3=33957

⇒99 p^3=33957

⇒p^3={33957}/{99}={3087}/{9}=343

⇒p^3=7×7×7=(7)^3

⇒p=7

The number are

2p=14,3p=21

and

4p=28

i.e.,

14,21,28

.

© examsiri.com

Go to Question:

Prev Question

Next Question