Question

which term of the AP 3,8,13,18..... will be 55 more than its 20th term? What's the answer

Answer 1

Here, we will use the formula to find the nth term i.e. aₙ=a+(n-1)d, where a is the first term ,aₙ is the nth term , n is the number of terms and d is the common difference.

Coming to the question.
a=3, d=5, aₙ=55 more than the 20th term i.e.
aₙ=55+{3+(20-1)5= 55+{3+95}=55+98= 153
according to formula,
aₙ= a+(n-1)d
153=3+(n-1)5
150=n×5-5
155=5n
therefore,n=31.(solved)

Answer 2

Answer:

Step-by-step explanation:

a=3, d=5, aₙ=55 more than the 20th term i.e.

aₙ=55+{3+(20-1)5= 55+{3+95}=55+98= 153

according to formula,

aₙ= a+(n-1)d

153=3+(n-1)5

150=n×5-5

155=5n

therefore,n=31.(solved)