Answer:
Charlie should use a stopwatch with minutes and seconds
Step-by-step explanation:
charlie should not count in his head as it is not accurate, he could count too fast or slow
Charlie should not look at that clock and the seconds will affect the 25 minutes, whether it be less or more
Charlie should not use an hourglass as he might flip it over too soon or quick and it's not very accurate
therefore using the stopwatch allows him to accurately and fairly keep track of the exact time
1 ) Billy walks 15 miles every day to soccer practice and he had 5 practices last week.
We know that, 1 mile = 1760 yards
So, 15 miles = (15× 1760) yards = 26400 yards
Thus the total distance walked in 5 practices will be: 
2) Mark's current age is
years
So, his age was in 10 years ago 
Given that, his current age is 3 times his age 10 years ago.
So, the equation to represent this situation will be : 
Answer:
4
Step-by-step explanation:
ok