Aptitude - Surds and Indices - Discussion

Discussion Forum : Surds and Indices - General Questions (Q.No. 13)
13.
If m and n are whole numbers such that mn = 121, the value of (m - 1)n + 1 is:
1
10
121
1000
Answer: Option
Explanation:

We know that 112 = 121.

Putting m = 11 and n = 2, we get:

(m - 1)n + 1 = (11 - 1)(2 + 1) = 103 = 1000.

Discussion:
13 comments Page 2 of 2.

Kanishka Roy said:   3 years ago
This is wrong method because the value of m can easily be -11.

Ali said:   3 years ago
But it is given that it is a whole number so it can't be negative (-11).

Am I right?

Asad said:   3 years ago
@All.

It's surds and indices math.

The square root should be surds. That's why we cant take -11, 121.


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