True or false: all circles are similar

How to do this , and can some one explain

An initial investment of $100 is now valued at $150. the annual interest rate is 5%, compounded continuously. the equation 100e0.05t = 150 represents the situation, where t is the number of years the money has been invested. about how long has the money been invested? use your calculator and round to the nearest whole number. years

Which letters from the table represent like terms? a and b b and c a and d b and d