Flag Magical Mathematics[Interesting Approach]> Mind-BLOWING sum...
question mark

which of the following has the maximum value?
a) 5^15
b) 6^14
c) 3^21
d) 2^30

PLEASE EXPLAIN :)  

AMIN II , 13 Years ago
Grade 10
anser 3 Answers
Ashwin Muralidharan IIT Madras

Last Activity: 13 Years ago

Hi Amin,

See 2^30 = (2^2)^15 = 4^15.... so < 5^15.

Next consider 3^21 = (3^3)^7=27^7

where as 6^14 is (6^2)^7 = 36^7

So 3^21<6^14.

 

Between 5^15, and 6^14.

Now consider (6/5)^14 = (1.2)^14 which is greater than (1.2)^12 = (1.2^4)^3

Now 1.2^4>2

so 1.2^12>8

 

So clearly (6/5)^14>5

so 6^14/5^14>5

So 6^14>5^15.

 

Hence 6^14 is the greatest.

 

All the best.

Regards,

Ashwin (IIT Madras).

Sathya

Last Activity: 13 Years ago

I think b is the correct option .The reason is 6^21 can be written as 2^21 x 3^21.It is greater than c and d for sure,the left one is option a.option a is surely lesser than b(as u can see).So b is the answer.Please post these type of questions,i will be ready to answer.

Sathya

Last Activity: 13 Years ago

I think so option b is the right answer.Is it correct?If yes,ill explain to you

Provide a better Answer & Earn Cool Goodies

Enter text here...
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments


Ask a Doubt

Get your questions answered by the expert for free

Enter text here...