is y an integer

is the ans B?

ri2007 wrote:is the ans B?

ans is E. both statements give values the satisfy and go against the condition..

If x^2+5y=49, is y an integer

1) 1<x<4
INSUFF

2)x^2 is an integer

this means that 5y must be an integer which is possible if y is an integer or y is a decimal like abc.2
INSUFF

Combine we dont get much here coz again y can be a integer or a decimal

INSUFF E

I agree that the answer should be E. Here's my approach:

I rewrite the equation to isolate y by itself on one side.

y = (49-x^2) / 5

which means that in order for y to be an integer, 49 - x^2 must be a multiple of 5 (5, 10, 15, 20, and so forth).

statement 1) 1<x<4 INSUFFICIENT because unless x is the integer 2 or 3, 49-x^2 will NOT be divisible by 5 (the question does not specify that x has to be an integer).

statement 2) x^2 is an integer. INSUFFICIENT Now, x^2 can be any integer- try plugging in some simple integers:

49-2 = 47, NOT a multiple of 5
49-4 = 45 IS a multiple of 5

Statement 1 & 2 together:

At first glance, i thought that answer would be C because 49-2^2 and 49-3^2 are both multiples of 5. But don't forget that even if x^2 is an integer, x itself may be a fraction. INSUFFICIENT

why is A insufficient. the question jst asked if y is an integer and not for the value of y

Well lalwalx A is insufficient because it says x is between 1 and 4 so here we should also consider the possibility of x being a decimal like 2.3,3.4 etc and so y may not be an integer but if u take x as 2 or 3 then y will be an integer and so its INSUFFICIENT.