What is the 25th term of the arithmetic sequence where a1=8 and a9=48 ? answers to choose from. a)113. b)118. c)123. d)128

First we need to find "d" which is difference between any 2 successive members of the sequence. Because the sequence is arithmetic that means that the difference between any 2 successive members is same and constant.

This is the formula for any member of sequence at position "n"
An = A1 + (n-1)*d
d = (a9 - a1)/(9-1)
d = 5

Now we calculate 25th member:
a25 = a1 + (25-1)*5
a25 = 128

Answer is d)

At a constant it will take one hour to travel 32 mi.at that speed it will take 1/2 hr to travel the remaining 16 mi.it will take 1+1/2 hr to travel the 48mi @ 32mph.so 1 hr = 60 min& 1/2 hr = 30 min1+1/2 hr = 90 min.there are 60s in each 90 × 60 = 3600 seconds.the real question seriously is he why are they driving so slow? ! lol.