2013 UNCO Math Contest II Problems/Problem 7

Problem

Suzie and her mom dry half the dishes together; then mom rests, while Suzie and her dad dry the other half. Drying the dishes this way takes twice as long as when all three work together. If Suzie’s mom takes $2$ seconds per dish and her dad takes $5$ seconds per dish, how long does Suzie take per dish?

Solution

$10$ seconds per dish

See Also

2013 UNCO Math Contest II (ProblemsAnswer KeyResources)
Preceded by
Problem 6
Followed by
Problem 8
1 2 3 4 5 6 7 8 9 10
All UNCO Math Contest Problems and Solutions