I need help on math (polz dont give helpless answer)

Find all the values of x that make 0.1x + 0.25(102 - x) < 17.10 true.

Fredrick designed an experiment in which he spun a spinner 20 times and recorded the results of each spin

Atorch and a battery cost 2.50 altogether.the torch costs 1.50 more than the battery.what fraction of the total price is the torch? give your answer in its simplest form.