Word Problems Flashcards
1
Q
Algebraic Translations
A
- Backsolve or translate into a 2-equation system and solve algebraically?
- Solve systems with substitution (isolate a variable) or by elimination
(stack the equations and then add or subtract) ?
“of” = multiply
“percent” = 1/100
“verb” = equal sign
“ratio of x to y” = x/y
“total” = sum
“8 less than x” = x - 8
“there are __ as many ..” = __ goes on 2nd thing
(there are 2/3 as many boys as girls —> b = 2/3g)
2
Q
Rates/Work/Distance
A
3
Q
Statistics
A
see “avg”? calculate sum
- range: diff between highest & lowest data points
- median: arrange in order. If odd # of things, median is the middle data
point. If even # of things, median is the avg. of middle two data points.
- standard deviation: need distance of each data point from average.
the farther the data points are from avg, the bigger the standard deviation - if avg is 40 and standard deviation is 3, then the interval within one
standard deviation of the mean is 37 to 43. - weighted averages (the distance the middle number is from each
endpoint is the ratio, in reverse) 20% of boys and 50% of girls at my
school drink tea. Overall, 33% of students drink tea.
(33 is 13 away from 20. 33 is 17 away from 50. So ratio of B:G is 17:13)
4
Q
Evenly Spaced Sets
A
Median = Average (midpoint of the set)
Adding up evenly spaced sets: Sum = (Avg)*(#)
- Avg = Avg of the 1st and Last term
- # of terms = (Range/Spacing) + 1
5
Q
Overlapping Sets
A