logo

Crowdly

Browser

Додати до Chrome

Questions Bank (1238229 total)

Consider the following theorem:

The sum of two positive even integers is also a positive even integer.

What, if anything, is wrong with the following attempt at proving this theorem?

Proof.

Start by choosing the smallest two positive even integers, 2 and 2. 2 + 2 = 4, which is also even. Then try 2 + 4 = 6, which is also even. Then 2 + 10, 2 + 12, etc., all of which add up to even totals. Then try adding 4 + 4 = 8, 4 + 6 = 10, and so on. All the resulting sums, for any two pairs of positive even integers, add up to an even integer. Therefore, the sum of two positive even integers is also a positive even integer.
0%
0%
0%
0%
0%
Переглянути це питання

What, if anything, is wrong with the following sequence of proof steps?

  1. We already know that if A and B are both true, then C is also true.
  2. Our initial assumptions state that A is true, but B is false.
  3. Therefore, C is false.

0%
0%
0%
0%
Переглянути це питання
Which of the following would not be a valid step to include as part of a proof?
0%
0%
0%
0%
Переглянути це питання

If and   then is equal to:

100%
0%
0%
0%
0%
Переглянути це питання
Переглянути це питання
Переглянути це питання

If d1 and d2 are doubles with valid values, what is wrong with the following expression?

"answer = " + (d1 < d2)

0%
0%
0%
100%
0%
Переглянути це питання

If the value of x is 20, what does this expression evaluate in Java?

0 <= x < 30

0%
100%
0%
Переглянути це питання

What left operand value and right operand value respectively does the multiplication operator operate on in the following expression? You can assume i has the initial value of 5.

i-- * i--

Hint: try it out in IntelliJ and work backwards to deduce what must have happened.

100%
0%
0%
0%
0%
Переглянути це питання

If a fineDay is defined as a day which is not raining, where the maximum temperature is no less than 20 and no greater than 25, which expression would define a fineDay?

0%
0%
0%
100%
0%
0%
Переглянути це питання