3rd questions :/ HELP
A 46 gram sample of a substance that's a by-product of fireworks has a k-value of 0.1374.
Find the substance's half-line, in days.
Round to the nearest tenth.

Question

3rd questions :/ HELP 
A 46 gram sample of a substance that's a by-product of fireworks has a k-value of 0.1374. 
Find the substance's half-line, in days. 
Round to the nearest tenth.

anonymous · Answer

ok we get the picture now?  go straight to the answer.  it is 
$$-\ln(.5)\div0.1374$$ use a caclulator

anonymous · Answer

natural log of one half divided by the natural log of k, get rid of the minus sign

anonymous · Answer

to the tenth it is 50.4 but you should check in case i give you the wrong answer

anonymous · Answer

50.4 is incorrect