What ratio equivalent to 10 : 85 a)20/170 b)2/15c)5/42d)20/94

The last time i bought this product , it cost $20.00 but it looks like it cost 29. 60 today? what is the increase

For the rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78. for an 10 month period, the last term is and the series sum is . for a 15 month period, the last term is and the series sum is . for a 20 month period, the last term is and the series sum is

Me with this one question, and i'll upvote the brainliest answer