4 HIKING: At 7:00 A. M., two groups of hikers begin 21 miles apart and head toward each other.
The first group, hiking at an average rate of 1.5 miles per hour, carries tents, sleeping bags,
and cooking equipment. The second group, hiking at an average rate of 2 miles per hour,
carries food and water. Let t represent the hiking time. (Non-anonymous question) * r.

White shapes and black shapes are used in a game. some of the shapes are circles. while the rest are squares. the ratio of the number of white shapes to the number of black shapes is 5: 11. the ratio of the number of white cicrles to the number of white squares is 3: 7. the ratio of the number of black circles to the number of black squres is 3: 8. work out what fraction of all the shapes are circles.