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 2 of 4.
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)
Sk.Rahul Basha said:
7 years ago
4th proportion formula.
d = bc/a.
Here. a=5,b=8,c=15,
Now submit in formula.
d=8*15/5=24.
d = bc/a.
Here. a=5,b=8,c=15,
Now submit in formula.
d=8*15/5=24.
(1)
Manish said:
6 years ago
Product of means = product of extremes.
(1)
Bii said:
6 years ago
In that case 8/15 and 15/24 are not equal. The answer is 28.
(1)
Rahul v said:
4 years ago
The number of proportional are only in even numbers that's why they are proportional.
(1)
Shiv said:
1 day ago
5 + 8 + 15 = 28.
And find the 4th ratio.
So, 28 - 4 = 24 is the answer.
And find the 4th ratio.
So, 28 - 4 = 24 is the answer.
Riba said:
9 years ago
@Kirshna.
The answer is 32.
8/15 = x/60.
The answer is 32.
8/15 = x/60.
Jaskaran said:
2 decades ago
How come 5x ? Please explain in detail.
Hanson said:
1 decade ago
Better still:
It will be split this way: 5:8=> 15:x.
Hence, the common factor is 15/5 = 3.
Thus, x/8 = 3.
x= 8*3 =24.
It will be split this way: 5:8=> 15:x.
Hence, the common factor is 15/5 = 3.
Thus, x/8 = 3.
x= 8*3 =24.
Malli said:
2 decades ago
There is 5:8:15:x then as for formula
1st x 4th=2nd x 3rd
i.e 5*x=8*15(it is a formula)
there four x=24
1st x 4th=2nd x 3rd
i.e 5*x=8*15(it is a formula)
there four x=24
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