Difference between revisions of "2002 AMC 8 Problems/Problem 18"
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+ | ==Problem== | ||
Gage skated 1 hr 15 min each day for 5 days and 1 hr 30 min each day for 3 days. How long would he have to skate the ninth day in order to average 85 minutes of skating each day for the entire time? | Gage skated 1 hr 15 min each day for 5 days and 1 hr 30 min each day for 3 days. How long would he have to skate the ninth day in order to average 85 minutes of skating each day for the entire time? | ||
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==Solution== | ==Solution== | ||
− | Converting into minutes and adding, we get that she skated <math>75*5 +90*3 +x=375 +270 +x=645 +x</math> minutes total, where x is the amount she skated on day 9. Dividing by 9 to get the average, we get <math>\frac{645+x}{9}=85</math>. Solving for x, <cmath>645+x=765</cmath> <cmath>x=120</cmath> Now we convert back into | + | Converting into minutes and adding, we get that she skated <math>75*5 +90*3 +x=375 +270 +x=645 +x</math> minutes total, where x is the amount she skated on day 9. Dividing by 9 to get the average, we get <math>\frac{645+x}{9}=85</math>. Solving for x, <cmath>645+x=765</cmath> <cmath>x=120</cmath> Now we convert back into hours and minutes to get <math>\boxed{\text{(E)}\ 2\ \text{hr}}</math>. |
+ | |||
+ | ==See Also== | ||
+ | {{AMC8 box|year=2002|num-b=17|num-a=19}} |
Revision as of 20:04, 23 December 2012
Problem
Gage skated 1 hr 15 min each day for 5 days and 1 hr 30 min each day for 3 days. How long would he have to skate the ninth day in order to average 85 minutes of skating each day for the entire time?
Solution
Converting into minutes and adding, we get that she skated minutes total, where x is the amount she skated on day 9. Dividing by 9 to get the average, we get
. Solving for x,
Now we convert back into hours and minutes to get
.
See Also
2002 AMC 8 (Problems • Answer Key • Resources) | ||
Preceded by Problem 17 |
Followed by Problem 19 | |
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 | ||
All AJHSME/AMC 8 Problems and Solutions |