A bacteria culture starts with 200 bacteria and in 1 hour contains 400 bacteria. How many hours does it take to reach 2000 bacteria?

At 0hr it was 200 bacteria

At 1 hr it doubled and was 400

Means: at every 1 hr the population of the bacteria doubles

400 bacteria = 1hr

2000 bacteria = X

X = 2000 × 1 / 400

X = 5 hrs

lizards have adapted to life in the desert. some desert lizards have toes with spiny scales to them run across the sand without sinking. some use the sand to hide from predators, or to search for small animals that they prey upon.