I can answer that... no. Why? I tried to help my 5th grader with his Math homework and my head was spinning just reading the question. Who, what, when, where.... WHAT? Basically, I said, "Huh?"
I told my son, "Wait until your dad gets home so he can help you."
Luckily, my husband was able to help him. Here is one of the homework questions. I will post the answer in a few days.
The sad part is that I have a teaching degree. HOWEVER... my speciality was early childhood education. Which means, I'd rather deal with the kindergartners than the 5th graders.
Stephan told his biology teacher his conjecture that the terrible year of cicadas occurred because 12-yr and 17-yr locusts came out at the same time. The teacher thought Stephan conjecture was probably incorrect, because cicadas in a particular area seem to be either all 13-yr locusts or all 17-year locusts, but not both. Stephan read about cicadas and found out that they eaten very quickly by lots of predators. However, cicadas are only in danger if their cycle occurs at the same time as the cycles of their predators. Stephan suspects that the reason there are 13-yr and 17-year locusts buy not 12-yr, 14-yr, or 16-yr locusts has to do with the predator cycles.
a. Suppose cicadas have predators with 2-yr cycles. How often would 12-year locusts face their predators? Would life be better for 13-yr locusts?
answer: The 12 year locusts would encounter the predators every time they emerged or never... depending if it was a 2 year cycle that overlapped with the predators or not.
b. Suppose 12-yr and 13-yr locusts have predators with both 2-yr and 3-yr cycles. Suppose both kinds of locusts and both kinds of predators came out this year. When would the 12-yr locusts again have to face both kinds of predators at the same time? What about the 13 yr-locusts? Which type of locust do you think is better off?
The 13 year locusts would encounter them every other time they came out depending if it was an even or odd year in the cycle. so it could be better (no predators) or worse (predators) than the 12 year locusts!
On the part about 2 year and 3 year cycles.... 12 year locusts meet their predators every time they come out (2 and 3 are factors of 12). 13 year locusts only every other time they emerge (just luck of the cycle). So it will be 6 cycles or 78 years before the 13 year locusts have to face both predators again.