Solve the problem. Martha can rake the leaves in her yard in 4 hours.  Her brother can do the job in 2 hours.  How long will it take them to do the job working together?

40) Which type of microscope provides tremendous (100,000-fold) magnification and enables viewing of fine internal structural details of cells? A) light microscope B) scanning electron microscope C) transmission electron microscope

Solve the equation. 3x+53-5xx-3=x{“version”:”1.1″,”math”:”3x+53-5xx-3=x”}

Encountering a word not immediately recognized, the students says “v-e-t- vet” What process is this student using to decode?

About what percentage of U.S. students are estimated to have attention deficit disorder (ADD)? 

Briefly explain why it is important to select the appropriate level of reading materials for your students. Your answer should be a minimum of 2 sentences.

22) Which one of the following statements is TRUE regarding the structure of the atom? A) The nucleus is composed of equal numbers of positively charged particles and negatively charged particles. B) All electrons are located at the same distance from the nucleus. C) In small elements, such as carbon, electrons have a positive charge; in larger elements, such as barium, electrons have a negative charge. D) Most of the mass of an atom is due to its protons and neutrons.

What is the value of Area B in Scenario 2?

What is the the value of Area A in Scenario 2?

21) A mad scientist has ripped apart an atom and collected all the subatomic particles located in the nucleus of the atom. Which one of the following has he collected? A) electrons B) protons C) protons and neutrons D) electrons and protons