Aptitude - Surds and Indices - Discussion
Discussion Forum : Surds and Indices - General Questions (Q.No. 11)
11.
| (243)n/5 x 32n + 1 | = ? |
9n x 3n - 1 |
Answer: Option
Explanation:
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Discussion:
10 comments Page 1 of 1.
Raj said:
4 years ago
243 can be written as 3^5,
a^x+y= a^x*a^y,
a^x-y = a^x/a^y. (a^x)y=a^xy,
According to those formula we can expand the question like this,
[(3^5)^n/5 * 3^2n *3]/ 9^n*3^n/3.
Simplify
3^n * 3^2n *9/3^2n * 3^n,
3^3n *9/ 3^3n =9.
a^x+y= a^x*a^y,
a^x-y = a^x/a^y. (a^x)y=a^xy,
According to those formula we can expand the question like this,
[(3^5)^n/5 * 3^2n *3]/ 9^n*3^n/3.
Simplify
3^n * 3^2n *9/3^2n * 3^n,
3^3n *9/ 3^3n =9.
Yuki said:
4 years ago
How does this 3^3n-3n-1+1 become 9? Please explain me.
Mangesh said:
6 years ago
3^3n+1/3^3n-1,
3^(3n+1-3n-1),
3^1 = 3.
3^(3n+1-3n-1),
3^1 = 3.
Aziz said:
7 years ago
3^(3n+1)-(3n-1),
So it will become 3^(3n+1-3n+1).
Because (-)(-) will become(+).
So it will become 3^(3n+1-3n+1).
Because (-)(-) will become(+).
Shubham said:
8 years ago
Yes I agree but sub n=1, then its easy.
Gajanan said:
8 years ago
Yes, agree @Karthik.
Karthik said:
8 years ago
But, if you substitute n=1 it becomes 9.
Karthik said:
8 years ago
Yes, you are right @Akash.
Akash ajith said:
9 years ago
It is actually 3 raised to 3x + 1 - 3x - 1.
Gourav Shrivastava said:
9 years ago
= 3^(3n + 1) / 3^(3n - 1) ,
= 3^(3n + 1 - 3n + 1) ,
= 3^2 = 9.
How is it formed?
= 3^(3n + 1 - 3n + 1) ,
= 3^2 = 9.
How is it formed?
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