Question

find the 11 th term from the last of the A.p series gives below A.p :10,7,4,...........,-62.

Answer 1

of the AP :-

first term = 10
common difference = 7-10 = -3
last term = -62

11 th term from the last
= al - (n-1)(d)
[because it is from the last]
=-62 - (11-1)(-3)
=-62 + 30
= - 32

Answer 2

a(n)= a+ (n-1)d .........(1) [formula for nth term of AP]

Since they asked from the last term th series should be written in opposite direction.

-62..........,4,7,10

From the above AP series, we get:
a=-62 (first term of the AP series) ＜since they asked from the last of AP＞
d= secound term-first term (or) or subtract any consecuent terms(right term-left term)

=10-7= 3
n=11 (the term.u need to find)

Hence from the formula of nth term:

11th term= -62+ (11-1)× 3 using.formula.......(1)
11th term= -62+ (10× 3)
= -62+30= -32

Hence the 11th tem from the last of the AP series will be -32