"Please help me win in 3 minutes please"

Not everyone will be on the app at the time you post a question. Typically, a question will be answered around half an hour, one hour or a few hours after being posted since time is taken to read questions and answer. There are 12 sub-questions which you have posted, and from the time the first person sees this to the time the person submits the answer, it would likely be more than 3 min.

I just came to this page, more than ten hours after you posted this.

10 tenths = 10 x 0.1 = 1

15 tenths = 15 x 0.1 = 1.5

1 ten 6 ones 8 tenths
= 10 + 6 + 0.8
= 16.8

3 tens 2 ones 7 tenths
= 30 + 2 + 0.7
= 32.7

5 tens 8 tenths
= 50 + 0.8
= 50.8

62.8 = 60 + 2 + 0.8
i.e. 6 tens 2 ones 8 tenths

Using similar logics,

5.3 = 5 + 0.3 because 5 is in the ones place (and therefore has a value of 5) and 3 is in the tenths place (and therefore has a value of 0.3)

(break them down into the values of their digits, whether they are in the tens place, ones place, tenths place etc)

12.7 = 10 + 2 + 0.7

96.5 = 90 + 6 + 0.5

90.8 = 90 + 0.8

100 + 20 + 5 + 0.6 = 125.6

73.4 = 70 + 3 + 0.4