Use the A=Pe^rt equation. A is the end amount, so it's 1892. P is the original amount, 1700. E is a constant, around 2.72. R is the growth constant. T is the time that passed, 3 hours. You can substitute the givens into the equation and get 1892=1700e^(3r). Divide by 1700 to isolate the e. This leaves you with 1892/1700=e^(3r). Do the natural log of each side cancel the e and bring the exponent down. This leaves you with ln(1892/1700)=3r. Divide by 3 to isolate r. ln(1892/1700) is .1. .1/3 is .03333. Multiply by 100 to get a percent. 3.33 percent is your final answer.
If the probability of drawing a red card is 3/10, then if we take this fom a whole, 10/10, we can find the probability of not choosing a red card. 10/10-3/10=7/10
The probability of not drawing a red card is 7/10 or 70%.