Toni has exactly $2.00 in nickels and dimes. she has twice as many dimes as nickels. how many of each does she have?

Pls! does anybody know a shortcut for answering these types of questions in the future?

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

Could someone with number 1 and 2