Agroup of four people has to cross a bridge. it is dark, and they have to light the path with a flashlight. no more than two people can cross the bridge simultaneously, and the group has only one flashlight. it takes different time for the people in the group to cross the bridge: chris crosses the bridge in 1 minute, tracy crosses the bridge in 2 minutes, ashley crosses the bridge in 5 minutes, jalen crosses the bridge in 10 minutes. how can the group cross the bridge in 17 minutes?

Step-by-step explanation:

Only two people can cross the bridge at the same time.

Chris takes 1 minute, Tracy takes 2 minutes, Ashley takes 5 minutes, Jalen takes 10 minutes.

Step 1: To make sure they all cross before 17 minutes is exceeded.

First, send Chris (the fastest) and Jalen (the slowest) together.

17 - 1 = 16

Chris crosses in 1 minute, Jalen, is still crossing (9 minutes left). 16 minutes left in all.

Next, Ashley crosses the bridge (5 minutes)

16 - 5 = 11

Ashley crosses with 11 minutes left, Jalen still has 4 minutes left, 11 minutes left in all.

Finally, Tracy crosses. Jalen would finish his crossing (4 minutes left). 11 minutes left in all.

11 - 4 = 7

The whole group costs with 7 minutes left in all

~

answer: the answer is one of

step-by-step explanation:   we are given to write a proper fraction where the whole is divided into an even number of equal parts less than ten, and an odd number of those parts exist.

an even number less than 10 may be one of 2, 4, 6 or 8. so, the whole may be one of these four evens.

now, an odd number of these parts must exist, so the numerator must be an odd number, one of 1, 3, 5 or 7. it cannot be 9 because then the fraction will become improper.

thus, our fraction may be one of the following