Five hundred grams of a particular radioactive substance decays according to the function \( m(t)=500 e^{-t / 400} \), where \( t \geq 0 \) measures the time in years. When does the mass of the substance reach 10 grams? Round to the nearest year.

1. \( 3 x[4 x(3 x-4 y)+2 x(3 x-4 y)+2 x(3 x-4 y)] \)

If you randomly select a card from a well-shuffled standard deck of 52 cards, determine the probability that the card you select is a King. a) Write your answer as a reduced fraction. b) Write your answer as a decimal, rounded to the nearest thousandth. c) Write your answer as a percent. Round to the nearest tenth of a percent as needed. \( \% \)

Solve the following quadratic inequality: \( 3 x^{2}+2 x-1 \geq 0 \) Write your answer in interval notation. Enter DNE if there is no solution.

Determine the inverse function of \( f(x)=5^{x}+1 \).

A person has the following fixed income and expenses: Income: \( \$ 7226.93 \); house payment: \( \$ 1939.48 \); utilities: \( \$ 403.77 \); car payment: \( \$ 221.38 \); insurance: \( \$ 143.34 \); cell phone and Internet: \( \$ 133.88 \); furniture loan payment: \( \$ 92.75 \) How much is left per month for variable expenses and luxuries? Round to the nearest cent. The person has \( \$ \square \) left for variable expenses and luxuries.