Tommy has blue, green, and red marbles. The number of blue marbles
and green marbles combined total 25.
The number of blue and red marbles
combined total 30. There are twice as
many red marbles as green marbles.
How many green marbles does
Tommy have?
A. 5
B. 10
C. 15
D. 20

Lizette is training for a marathon. at 7: 00 she left her house and ran until 8: 30, then she walked until 11: 30. she covered a total distance of 18 miles. her running speed was six miles per hour faster than her walking speed. find her running and walking speeds in miles per hour.