Question

The ratio of the third and 6th term of an arithmetic sequence is 4 : 5.

a. Find the ratio of 7th and 11

th terms.

b. If the 11

th term is 60, then find its 16th term.



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Answer 1

Answer:

a)4:5

b)75

a)take the ratio of third term and sixth term = 4/5

now from that eqn find a=10d.

now put that in the eqn of a+6d

a+10d

and find the ration 16d/20d = 4/5

b) a + 10d = 60

10d+10d = 60

d= 3

now and a = 30

a+15d = 30+15*3=75.