Question

Find 10th term of the A.P $1,4,7,10,....$

Answer 1

Given A.P is

$1,4,7,10,.....$

first term of this A.P is $a_1=1$

second term of this A.P is $a_2=4$

common difference of an A.P is given by

$(i.e.,d=a_{n+1}-a_n)$

putting n=1 in above equation

$d=a_2-a_1=4-1=3$

hence common difference for this A.P is $d=3$

the nth term of an A.P is given by.

$a_n=a_1+(n-1)d$

hence, for calculating 10th term of A.P $a_{10}$ put n=10 in above equation

$a_{10}=a_1+(10-1)d$

$a_{10}=1+9\times 3$

$a_{10}=1+27$

$a_{10}=28$