Question

which term of the progression 20, 19 1/4,18 1/2,17 3/4,... is the first negative term?​

Answer 1

Answer:

a= 20

d= 19 1/4 - 20

= -3/4

nth term =0

a + (n-1)d = 0

20 + (-3n+3)/4=0

n=27 (approx)

thus the 28th term is negative

Answer 2

a=20, d=19 1/4-20=77/4-20=-3/4

an=a+(n-1)×d

= 20+(n-1)×-3/4

=20+(-3n+3)/4

=80-3n+3/4

=83-3n=0

=3n-83=0

n=83/3

n=27.66=28

so, 28th term will be the first negative term.