Question

Find the seventh term of the sequence 40, 0.4, 0.004, ....

Answer 1

Answer:

Answer: Option d.  4×$10^{-11}$

Step-by-step explanation:

In any sequence where ratio of the terms is given we always use the formula

A(n) = A(1)$r^{n-1}$

Here A(n) is the term n

A(1) is the first term

n= number of trms

and r = ration of the terms

Here the given sequence is 40,0.4,0.004........

So A(1) = 40

Ratio 'r' of second and first term is =0.4/40=1/100

We have to find 7th term so n=7

Now we put the values in the formula

A(7) = $40(1/100)^{7-1}$

        =$40(1/100)^{6}$

        = $40/100^{6} =40/10^{12}$

        = 40×$10^{-12}$

        = 4×$10^{-11}$