Aptitude - Ratio and Proportion - Discussion
Discussion Forum : Ratio and Proportion - General Questions (Q.No. 13)
13.
The fourth proportional to 5, 8, 15 is:
Answer: Option
Explanation:
Let the fourth proportional to 5, 8, 15 be x.
Then, 5 : 8 : 15 : x
5x = (8 x 15)
| x = | (8 x 15) | = 24. |
| 5 |
Discussion:
34 comments Page 2 of 4.
Samim said:
1 decade ago
5:8 = 15:x.
5/8 = 15/x.
5x = 15*8.
x = 90/5.
x =18.
5/8 = 15/x.
5x = 15*8.
x = 90/5.
x =18.
Shipra said:
1 decade ago
Hello guys!
Its given,
5:8:15:x.
Where we take x as constant.
Now,
5/8 = 15/x.
=> 5 = (15*8)/x.
On cross multiplication we get,
x = (15*8)/5.
x = 3*8.
x = 24.
Its given,
5:8:15:x.
Where we take x as constant.
Now,
5/8 = 15/x.
=> 5 = (15*8)/x.
On cross multiplication we get,
x = (15*8)/5.
x = 3*8.
x = 24.
Sumitra said:
1 decade ago
It should be like this 5:8::15:x.
Then 5/8 = 15/x.
x = 15*8/5.
x = 24.
Then 5/8 = 15/x.
x = 15*8/5.
x = 24.
Isaacs nyondo said:
1 decade ago
It is really supposed to be.
5:8 = 15:x.
It means that they are terms of a sequence.
Then:
5/8 =15/x.
x = 15*8/5.
x = 24.
5:8 = 15:x.
It means that they are terms of a sequence.
Then:
5/8 =15/x.
x = 15*8/5.
x = 24.
Main said:
10 years ago
It should be 8x15 = 90.
5 then the answer is 18 because 90/5 = 18.
5 then the answer is 18 because 90/5 = 18.
Sasulya said:
9 years ago
Just see diff. between 3 numbers and all are odd.
5 and 8 = 3 odd number.
8 and 15 = 7 odd number.
Then next odd num after 7 is 9.
5 and 8 = 3 odd number.
8 and 15 = 7 odd number.
Then next odd num after 7 is 9.
Ramesh said:
9 years ago
They asked. How 5th proportional?
Akshay said:
9 years ago
@All.
There is no any formula they just use a simple logic of a/b/c/d i.e. (a/b) = (c/d) if we pass this term in side the equal to sign i.e.(a*d) = (b*c).
There is no any formula they just use a simple logic of a/b/c/d i.e. (a/b) = (c/d) if we pass this term in side the equal to sign i.e.(a*d) = (b*c).
(1)
Kirshna said:
9 years ago
If 60 is the fourth proportional to 8, 15 and x ; find x.
Please solve this.
Please solve this.
Riba said:
9 years ago
@Kirshna.
The answer is 32.
8/15 = x/60.
The answer is 32.
8/15 = x/60.
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