compound interest equation for annually compounded

A=final amount
P=principal
r=rate in decimal
t=time in years
given that
A=1550
P=1000
r=5.5%=0.055
find t

divide both sides by 1000

take ln of both sides

use ln rule 

divide both sides by ln(1.055)

using a calculator, we get that t=8.18544 yrs
so about 8.2yrs
Step-by-step explanation:
can I have actual options I can't figure it out with invalid options
Answer: AC = A'C'
Then you can use the hypotenuse leg theorem to say that the two triangles are similar
Step-by-step explanation:
Answer:
20
Step-by-step explanation:
0.5-0.4=0.1,0.1/0.5×100= 20
5/10=2
So 2 minutes per problem