Question

1. If X= {x : x is a multiple of 5} and Y = {x : x is a multiple of 7), then XnY is
(a) 0
(b) {x : x is a multiple of 2}
(c) {5, 7}
(d) {x : x is a multiple of 35)
95​

Answer 1

Answer:

d

Step-by-step explanation:

because all the multiple of 35 are also the multiple of 5&7.

For example

35 is the multiple of 35,5&7.

like this

70 is also multiple of 7,5&35...so on

Answer 2

Step-by-step explanation:

If y is a multiple of 5, 4y must be a multiple of 5 too.

3x = 200 - 4y = Multiple of 5 - Multiple of 5 = Multiple of 5

Since 3 is not a multiple of 5, x MUST be a multiple of 5.

Also, 4y is even. So 3x = Even - Even = Even

Since 3 is not even, x must be even.

Hence x must be a multiple of 10.