# Math Help - 2 Easy questions that for some reason I can't figure out!

1. ## 2 Easy questions that for some reason I can't figure out!

1.) Money gains interest at a rate of 50% every 4 years. What is the value of $5,000 after 6 months? After 7 years? 2.) Bacteria double every 30 minutes. How much must you have now in order to have 5 million bacteria in 45 mins? I don't know why, but these two are giving me trouble. I know you have to use them in the formula A = P(1+r)^t, but the conversions are throwing me off. Can anyone help?? 2. Ok, I figured out the first one... v= 5000 (1+0.5)^(1/8) =$5259.95 ; v= 5000(1+0.5)^1.75 = \$10165.52

Still stuck on the second question...

3. ## Bacteria Problem

If bacteria double in 30 minutes, then in 15 min (half the time) they multiply with the square root of 2.

x * 2 * sqrt(2) = 5 million

x= 5 million / 2 / sqrt(2)

hope it helps