Posted by **Lisa** on Tuesday, February 7, 2012 at 7:37pm.

Which argument is not valid?

1.) Given: a→b

a

Conclusion: b

2.) Given: a˅b

~b

Conclusion: ~a

3.) Given: a→b

~b

Conclusion: ~a

4.) Given: a→b

b→~c

Conclusion: a→~c

## Answer this Question

## Related Questions

- Chemistry - Use the data given below to construct a Born - Haber cycle to ...
- Chemistry - I think these I know how to do ....just want someone to check..still...
- Philosophy - HELP - How would you construct a proof to show that the following ...
- Philosophy - How would you construct a proof to show that the following ...
- Chemistry - Please help me! I don't know how to do this at all. Calculate the ...
- Chemistry - Given the following hypothetical equations, 2A + B → 3C + 2D...
- maths - A sequence is defined by un = 2×(−0.5)n + 3 (n = 1,2,3, . . .). ...
- maths - A sequence is defined by un = 2×(−0.5)n + 3 (n = 1,2,3, . . .). ...
- Math - . If 111 → 13, 112 → 24, 114 → 46, and 115 → 57, ...
- add maths - Function f and g are defined by f:x→4-x and g:x→px^2+q ...