Aptitude - Numbers - Discussion

Discussion Forum : Numbers - General Questions (Q.No. 121)

Numbers

121.

What is the unit digit in the product (3⁶⁵ x 6⁵⁹ x 7⁷¹)?

Answer: Option

Explanation:

Unit digit in 3⁴ = 1 Unit digit in (3⁴)¹⁶ = 1

Unit digit in 3⁶⁵ = Unit digit in [ (3⁴)¹⁶ x 3 ] = (1 x 3) = 3

Unit digit in 6⁵⁹ = 6

Unit digit in 7⁴ Unit digit in (7⁴)¹⁷ is 1.

Unit digit in 7⁷¹ = Unit digit in [(7⁴)¹⁷ x 7³] = (1 x 3) = 3

Required digit = Unit digit in (3 x 6 x 3) = 4.

Discussion:

39 comments Page 3 of 4.

Jignesh said: 9 years ago

@Jyothi.

Thanks for your clear explanation.

Prem said: 8 years ago

Thanks for your clear explanation @Jyothi.

Ashwini said: 7 years ago

How 7^4 ^17? please explain me clearly.

Gayathri said: 9 years ago

Thanks, @Jyothi. It's an easy way.

Madhusudhan said: 8 years ago

Anyone please explain (7^95-3^58).

Gjkk said: 1 decade ago

Why we take power of 7 is only 4?

Jenifer said: 9 years ago

Thanks you so much @Jyoti.

Himanahu said: 3 years ago

I think the answer is 1.

(1)

Krish said: 1 decade ago

Any other easy method?

Soundarya said: 8 years ago

Please explain 6^59=6.

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