The population of a local species of dragonfly can be found using an infinite geometric series where a1 = 48 and the common ratio is 1/4 . write the sum in sigma notation and calculate the sum that will be the upper limit of this population.

I think the letter is b but i am not sure

When rates are expressed as a quantity of 1, such as 2 feet per second or 5 miles per hour, they are called unit rates. if you have a multiple-unit rate such as 120 students for every 3 buses, and want to find the single-unit rate, write a ratio equal to the multiple-unit rate with 1 as the second term.