Answer:
The answer is d) 4d = 320 - 60 becasue d is the dollors he made per hour and the repairman worked for 4 hours so you multiply 4 times d and then you subtract 60 from the total to get your final answer. If you subtracted already then you would divide that answer by 4 then you would find out how much the repairman maid per hour.
Answer: D. 36, 108
Step-by-step explanation:
In the geometric series the ratio of two consecutive term is constant and this ratio is called the common ratio,
Let n be the common ratio of the given series,
Then the GP will be,
12, 12×n, 12×n×n, 324,
Again by the definition of Geometric series,

Thus, the required series is,
12, 12×3, 36×3, 324
= 12, 36, 108, 324
⇒ Option D is correct.