you can use a calculator if you want. No links please help this is very important i will give you brain thing if its correct

The tip would be $6.36

Explanation:

If the bill was $42.40, and you wanted to leave  15% tip

0.15 is the same as 15% and you multiple it by the amount to get your tip

explanation:

allergens: overstimulate the nerve system

neurotics: attack nerve cells

mutagens: damage or otherwise alter dna sequence

generators: cause defects during growth and development  

carcinogens: cause unchecked cell growth

i hope you get the idea according to me these are the effects that happened.

i feel as if they would both catch on before to long because they would see them to frequent