Question

For an A.P the first term is 7 and 6th term is 32.if the nth term is 72,find n

Answer 1

HERE FIRST TERM=a=7
6TH TERM=32
COMMON DIFF=(32-7)/(6-1)=25/5=5=d
nTH TERM=a+(n-1)d=72
i.e. 7+(n-1)5=72
i.e. 7+5n-5=72
i.e. 5n=72-2
i.e. n=14
i.e. 72 IS THE 14TH TERM