Question

find the ratio of 10th term from beginning and 20th term from the end of the ap:3,8,13,.......,253

Answer 1

Here's is your answer

Answer 2

Given:

We have given an A.P 3,8,13 up to 253.

To Find:

We have to find the ratio of 10th term and 20th term?

Step-by-step explanation:

We have First term of A.P is 3

• Common difference of A.P is given by the formula

       $d=a_2-a_1=8-3=5$

• We know the nth term of A.P is found by the formula

       $a_n=a+(n-1)d$

• Hence 10th term of A.P will be

        $a_1_0=a+9d\\a_1_0=3+9\times5\\a_1_0=48$

• Now for calculating the 29th term from last we will revese the A.P which is as  follow as

    First term,a=253

   Common difference, d=-5

 number of terms,  n=20

• Then 20th term will be given by

           $a_2_0=a+19d\\a_2_0=253+19\times(-5)\\a_2_0=253-95=158$

Hence the ratio of 10 th to the 20 th term form last is given as 48:158=24:79

Hence, the ratio is 24:79.