To mail a first class letter, the u. s. postal service changes $50 for the first ounce and $21 for each additional ounce. it costs $1.34 to mail your letter. how many ounces does your letter weigh

There clearly is a typo in the I assume the price for the first ounce is 0.50$, and then you pay 0.21$ for each additional ounce.

So, the price of a letter is

where is the number of additional ounces.

If you paid 1.34$, the equation is

So, your letter weights 4 additional ounces.

0.6, 3/5, and 6% are the 3 same portion.

but, when they're all changed to a decimal they would equal to 0.6.

hope this , good luck!

e^-kt = n/n0 = 0.79  

-kt = ln 0.79  

t = - ln 0.79/0.0001  

= 2357 years

step-by-step explanation: