This is very hard teacher didn't teach us yet

0.45

Step-by-step explanation:

Percentages are the number over 100 which is basically 45/100. This fraction can be converted into a decimal, as the decimal places are 0.(tenths 1/10)(hundredths 1/100). 45  going into the hundredths puts the 4 in the tenths and the 5 in the hundredths.

$3720

step-by-step explanation:

taxable income = $31000

as per the 2018-2019 us tax bracket, the tax rate is 12% for an individual whose taxable income is between $9,526 to $38,700.

so, the tax to be paid by him = 12% of 31000

= 0.12 * 31000     [12% converted to decimal as 0.12]

= $3720