CBSE BOARD X, asked by sandy496, 1 year ago

find the 20th term from last term of the AP 3,8,13,.....,253

Answers

Answered by Anonymous
96

Solution :


We have, l = Last term = 253

and,

               d = Common difference = 8 - 3 = 5

∴ 20th term from the end = l - (20 - 1)d

                                           = l - 19d

                                           = 253 - 19 × 5

                                           = 253 - 95 = 158

Answered by srimanthbalaji
43

a20=?

from last term so the AP becomes 253........,13,8,3

now, a=253

         d=8-13 =-5

an=a+(n-1)d

a20=253+(20-1)-5

       =253+19(-5)

       =253-95

       =158

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