The 20% tip on a $8 sandwich

$1.60 tip on a $8 sandwich

Step-by-step explanation:

SO to find percent

just multiply the number by the percent

Remeber the percent means x/100

SO in this case 20/100 or 1/5

So you can just multiply 1/5*8 and get 1 3/5.

If you convert 3/5 into a decimal

3 divided by 5

that is .6

SO add them up

1+0.6= $1.60

area of part 1:

a1=base*height/2=(8+2)*(8-2-2-1)/2=10*3/2=15 ft^2

area of part 2:

a2=length*width=(8+2)*1=10 ft2

area of part 3:

a3=length*width=8*2=16 ft2

total shaded area : a1+a2+a3=41 ft2

total area of the reactangle : a=16*8=128 ft2

total area of the nonshaded region : 128-41=87 ft2

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)