Aptitude - Surds and Indices - Discussion

Discussion Forum : Surds and Indices - General Questions (Q.No. 4)

Surds and Indices

If 5^a = 3125, then the value of 5^{(a - 3)} is:

125

625

1625

Answer: Option

Explanation:

5^a = 3125 5^a = 5⁵

a = 5.

5^{(a - 3)} = 5^{(5 - 3)} = 5² = 25.

Discussion:

18 comments Page 2 of 2.

Girish said: 1 decade ago

Above can be read as 5^a-3 = 5^a/5^3 = 3125/125 = 25

Tari said: 3 years ago

I am not getting this. Please explain me in detail.

(3)

Babu vijayendra kumar said: 8 years ago

I'm not getting this, anybody explain the logic.

(2)

Mandeep Mehra said: 7 years ago

5^a=3125.
5^a-3=5^a/5^3.
5^a/5^3=3125/125=25.

RAMESHA T S said: 8 years ago

5^(a-3)=(5^a)/(5^3)=3125/(5*5*5) = 25.

Girish said: 1 decade ago

Also 5a-3 = 5a/53 = 3125/125 = 25

Shridhar naik said: 1 decade ago

5^(a-3)=5^a*5^(-3)=3125/125=25

Dhika said: 6 years ago

Here, the value of 5^a=3125.

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