**Question:**

Find the lowest number in an AP such that the sum of all the terms is 105 and greatest term is 6 times the least...??

Or (n-1)d=5a

Also it is given that

n/2[2a+(n-1)d]=105

Also n/2*(a+l)= 105

[Where l is last term]

Now n/2*(a+6a)= 105

n/2*(7a)= 105 or n*a=30

Now , we will go by option if that is given.

Correct answer is 5, 10, 15....these 3's no. Are satisfy our condition.