[warrior]

Originally Posted by esjay

ive wasted whole of my evening on this one...i know the ans...sm1 pls post the soln
Find the largest integer which definitely divides a^(4*b+1) – a
a. 10 b. 5 c. 20 d.30

is the ans 10 (a)

[esjay]

Originally Posted by warrior

is the ans 10 (a)

nopes its d)
5 se divisibility kaise nikali???? yahin pe atak gaya hoon
its divisible by 2 n 3
hence ans is 2.3.5=30

[vinit456]

Originally Posted by esjay

ive wasted whole of my evening on this one...i know the ans...sm1 pls post the soln
Find the largest integer which definitely divides a^(4*b+1) – a
a. 10 b. 5 c. 20 d.30

Is it 30?

Took random values though and they were divisble by 30

Tried to work from a(a^2(2b)-1) but could'nt get anything conclusive........

VA

[Pragati Soni]

Plz clear my one doubt........

See I know that if a decimal fraction is

1) recurring & terminating=> Rational

2)nonrecurring & nonterminating=> Irrational

3) Nonrecurring & terminating=> Rational

But what abt

RECURRING & NONTERMINATING=>?

pLZ REPLY....

REGARDS,

[unique_1]

Originally Posted by esjay

ive wasted whole of my evening on this one...i know the ans...sm1 pls post the soln
Find the largest integer which definitely divides a^(4*b+1) – a
a. 10 b. 5 c. 20 d.30

ans 30
a^(4*b+1) – a= a[a^4*b-1] now look this is divisible by 2&3 trivial 2 see.
for this to be divisible by 5 if a=/=5k then {a^b}^4=1 (mod5) fermats th
or can even look with an alternative way that units digit of a^4*b wll be either 1or6.

[unique_1]

Originally Posted by Pragati Soni

Plz clear my one doubt........

See I know that if a decimal fraction is

1) recurring & terminating=> Rational

2)nonrecurring & nonterminating=> Irrational

3) Nonrecurring & terminating=> Rational

But what abt

RECURRING & NONTERMINATING=>?

pLZ REPLY....

REGARDS,

rational eg 1/3

[vikram_k51]

Can some1 pls explain this:

If (AB) x (AB) = XYA, then X stands for :

1.)3 2.)6 3.)4 4.)9


Thnx in anticipation.

[Mantri]

X= 3 in the above problem.

solution

for a 2 digit number to give a 3 digit square the tens digit has to be less than 4 . Now since A is the last digit of the squared number we have A = 1.

Now we get last digit 1 only for squares of numbers ending in 1 or 9 .

so AB = 11 or 19
(AB)x(AB) =121 or 361
implies X = 1 or 3 .
only 3 is in the options.

[cateyed10]

Originally Posted by Pragati Soni

Plz clear my one doubt........

See I know that if a decimal fraction is

1) recurring & terminating=> Rational

2)nonrecurring & nonterminating=> Irrational

3) Nonrecurring & terminating=> Rational

But what abt

RECURRING & NONTERMINATING=>?

pLZ REPLY....

REGARDS,

thrs nothing of "recurring & terminating" types coz recurring by definition is always non-terminating.
Rational => (recurring) OR(non-recurring & terminating)
Irrational => (nonrecurring & nonterminating)

anya

[Pragati Soni]

wud any one of u plz elaborate more on the solution............

Regards,
Pragati

Originally Posted by esjay

ive wasted whole of my evening on this one...i know the ans...sm1 pls post the soln
Find the largest integer which definitely divides a^(4*b+1) – a
a. 10 b. 5 c. 20 d.30