September Answer:
Problem: The Weather Service reported an unusually strange rainfall pattern. Each day a larger and larger amount of precipitation would fall. On the first day, local meteorologists reported 1/4-inch of rain. On the second day, .375 inches of rain fell -- 1.5 times as much as the day before. Every day 1.5 times as much precipitation fell as on the previous day. On what day would the area reach an accumulated total of six inches of rainfall?
Solution: On Day 7, the area reached an accumulated total of six inches of rainfall.
The strategy: Make a list or make a chart to find the pattern:
DAY |
NEW RAIN |
TOTAL RAIN |
Day 1 |
1/4-in. |
.25 in. |
Day 2 |
.375 in. |
.625 in. |
Day 3 |
.5625 in. |
1.1875 in. |
Day 4 |
.84375 in. |
2.03125 in. |
Day 5 |
1.265625 in. |
3.296875 in. |
Day 6 |
1.8984375 in. |
5.1953125 in. |
Day 7 |
2.8476562 |
8.0429587in |
Students Who Submitted
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