Graham puts $20 in his piggy bank every week. at the end of 39 weeks, he adds $100 to the piggy bank money and decides to do the following: buy some clothes and sports gear for $314.23 buy his mom a present for $123 divide the rest of the money equally among his three brothers use a calculator to find the amount of money each brother will get. $147.59

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)