Question

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

Answer 1

Answer:

98

Step-by-step explanation:

Here is the answer of your question

Answer 2

Answer:

given:

=> first term

= t1

= a

= 3

=>difference

= d

= t2- t1

= 8 - 3

= 5

=》 to find 20th term from the last

Step-by-step explanation:

we need to find how many term in an A.P,

Here, tn = 253, a = 3, d = 5

tn = a + (n - 1) × d

253 = 3 + (n -1) × 5

253 - 3 = (n - 1) × 5

250 = ( n - 1 ) × 5

(n - 1) = 250/5

(n - 1) = 50

n = 50 + 1

n = 51

In an A.P, there are 51 term,

to find 20th term from last

= 51th - 19th

= 32th

therefore, the 20th term from the last the last term is 32 .

n = 32

tn = a + (n - 1) × d

t32 = 3 + ( 32 - 1 ) × 5

= 3 + 31 × 5

= 3 + 155

= 158

therefore, the value of 20th term from the last term of an A.P. is 158.