let 10th term be x and 30th term be 3x.
now use formula sn = n/2(2a+(n-1)d
it doesn't seems easy..
is too hard
sorry can't .
the will iam i am going looking for forward for the use same time as i well and as a i will have to a few different to be do it not being to the same time to i am have any other questions or if need be to use have a off and to the be a able to the same right now to the see inside you have a any questions other that are not the intended recipient you are interested in the morning.