18% of 90 is what number

In exponential growth functions, the base of the exponent must be greater than 1,how would the function change if the base of the exponent were 1? how would the fiction change if the base of the exponent were between 0and 1

You have 37 coins that are nickels, dimes, and pennies. the total value of the coins is $1.55. there are twice as many pennies as dimes. find the number of each type of coin in the bank.

Jenny made a scale drawing of a city. the scale she used was 5 inches = 1 yard. what is the scale factor of the drawing?