Question

28 Which term of the sequence 20, 19, 18 ,17 ,……….. is the first negative term 3

Answer 1

Answer:

1

2

Which term of the sequence 20, 19 1/4, 18 1/2, 17 3/4,… is the first negative term?

Naveen Shekhar

Updated October 30, 2017

19 1/4 =77/4 Now,20-77/4 =3/4

18 1/2 =37/2 Now,77/4-37/2 =3/4

17 3/4 =71/4 Now,37/2-71/4 =3/4

So,we have a series where terms get decreased by 3/4 .Means it is A.P.series with a=20 and d=(-3/4).Let nth term be its first negative term.

=> 20 +(n-1)(-3/4) <0

{ in A.P.,nth term =a+(n-1)d

=> 80-3n+3 <0 => 83<3n =>83/3 <n

So, n =28

{first integer greater than 83/3 ~27.6 }.

And 28th term =20+(28-1)(-3/4)

=20+27×(-3/4) = -1/4 Ans.

Answer 2

Answer:

It's a decreasing sequence. Let's find the number of term which will be zero . Then the next integer will give negative term.

15 is the answer

Step-by-step explanation:

hope it's helpful