Question

If a and b are real numbers, and if a > b, and b = 3, then a 4. Which of the following is a counterexample to the assertion above?

Answer 1

a = -4.5
a = 4.1
a = 2.5
a = 3.5

Answer 2

@stgreen

Answer 3

do you know what counter example is in general?

Answer 4

Yes

Answer 5

what is it?

Answer 6

A counterexample is an example of something that disproves a claim. For example, if I said "All numbers are less than one million. Take 1 for example. Or 2. Or 3. Or 4." All you'd have to point out is a single counter-example like 2 million to disprove my claim.

Answer 7

oh

Answer 8

it says if a>b and b=3 then a is necessarily 4..
but you see a could be anything greater than 3..it can be 5,6,7,8 and so on..it can be 4.1..since 4.1>3

Answer 9

i know but i dont know how to answer the question

Answer 10

so its 4.1? @stgreen

Answer 11

i got it wrong it was 3.5

Answer 12

oh yea my bad 3.5 is closer than 4.1..3.5>3 too