Number properties

[4meonly]

Is a/b an integer?

(1) 4a/b is an integer
(2) 4b/a is an integer

OA E

[logitech]

Is a/b an integer?

(1) 4a/b is an integer

4(a/b) is integer

if it is 4, a/b = integer

if it is 5 , a/b is not an integer

INSUF


(2) 4b/a is an integer

if b/a = 1, 4b/a is an integer and a/b is an integer

if b/a is 2 , 4b/1 is an integer but a/b is not! (1/2)

(1+2)

a = 4 b = 8

4a/b = integer

4b/a = integer

a/b is not an integer

I learned this method from Cramya

[aj5105]

I got C as the answer.

Cramya,
could you please explain taking both together?

thanks!

[aj5105]

got it

I got C as the answer.

Cramya,
could you please explain taking both together?

thanks!

[cramya]

4a/b and 4b/a are integers and a/b is integer if a=6 and b=3


To prove insufficiency

Take a=2 b=4 for stmt I and stmt II a/b not an integer


Together

Again take a=2 b=4 a/b not integer
Take a=6 b=3 a/b integer

Hence E)

[4meonly]

Are there any methods without plugin numbers?
Algebraic?

[logitech]

Are there any methods without plugin numbers?
Algebraic?

Is a/b an integer?

(1) 4a/b is an integer

a/b=x

4X=K

X=K/4

If K is divisible with 4, X is integer
If not X is not an integer

(2) 4b/a is an integer

4/X=K

X=4/K

If 4 is divisible with K , X is integer if NOT it is not

Together

4/K=K/4

If K is 4 they X is integer

If K is not 4, X is not an integer