Question

Check whether ` 150` is a term of the AP : 11, 8, 5, 2...

Answer 1

given `a=11`
b=`8-11=5-8= -3`
lets say -150 is `r^(th) term`
so`a+(r-1)d= -150`
`11+(r-1)(-3)= -150`
`(r-1)*3= 161`
`r-1=161/3`
`r=161/2 +1 cancel(=) ` integer
so, -150 is not a term of a given AP