A machine can grade 30 tests in 2 minutes. At this rate, how long will it take the machine to grade 135 tests? 8 minutes

9 minutes

10 minutes

12 minutes

9 minutes

Step-by-step explanation:

(2 min(60 s/min)) / 30 test = 4 s/test

135 test(4 s/test) = 540 s

540s / 60 s/min = 9 min  

b. 6

step-by-step explanation:

we are given the table representing an exponential function.

we can see from the table that, as x is increasing, the value of y is increasing in the power of 6.

i.e. the following relation is obtained,

x = 1, y = 6

x = 2, y = 36 =

x = 3, y = 216 =

x = 4, y = 1296 =

x = 5, y = 7776 =

so, the geometric series obtained is .

thus, the common ratio is given by = = 6.

hence, the common ratio is 6.