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:
35 comments Page 3 of 4.
Manik said:
2 decades ago
Is this formula applicable for such other problems? What abt the formula of fifth, sixth or higher proportional?
Sai said:
2 decades ago
Formula must be used compulsory ? we can assume it as in series form as 5, 15, 25, 35.... In same manner 8, 18, 28......
Shrishti said:
1 decade ago
This is solved by proportional formula such as a:b :: c:d
Formula: a*d=b*c (as said find fourth proportional).
Formula: a*d=b*c (as said find fourth proportional).
Reethrose said:
1 decade ago
5:8::15:?
5*3=15
8*3=24
so the answer is 24.
5*3=15
8*3=24
so the answer is 24.
Priyankapatil said:
1 decade ago
How to find fifth proportional?
Azeem said:
1 decade ago
Assume a=5, b=8, c=15.
We all know the ad = bc.
a = bc/d, b = ad/c, c = ad/b.
Simillarly d = bc/a.
So 8*15/5 => 120/5 = 24.
We all know the ad = bc.
a = bc/d, b = ad/c, c = ad/b.
Simillarly d = bc/a.
So 8*15/5 => 120/5 = 24.
Divya said:
1 decade ago
Let the 4th proportional to 5:8::15:x.
Product of extremes = product of means.
5x = 8*15.
x = 120/5.
= 24.
Product of extremes = product of means.
5x = 8*15.
x = 120/5.
= 24.
Kirshna said:
9 years ago
If 60 is the fourth proportional to 8, 15 and x ; find x.
Please solve this.
Please solve this.
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.
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