The common difference is 4. If you look at the numbers 1 and 5, there is a difference of 4. If you look at 5 and 9, there is also a difference of 4. If you look at 9 and 13, there is a difference of 4. Therefore, in this arithmetic sequence, the common difference is 4.
Hey You!
This question is asking us, "75 is 75% of what number?"
75 × 100 / 75 = 100
The original cost was $100.
#420
because 70x4=420 within 300 and 500 and is greater than 400 which is a multiple of 100
