Given sequence: 56, 63, 70,..., 329 First find the common difference: d=a2-a1 d=63-56 d=7 Formula: an=a1+(n-1)d First find the number of terms. 329=56+(n-1)7 329=56+7n-7 329=49+7n 280=7n 40=n or n=40 We have to find 40-11=29 th term ( 11 th term from the end) a29= 56+(29-1)7 a29=56+(28)7 a29=56+196 a29=252
