4 = 2 * 2
Multiplying by 2 is the same a doubling.
Since 4 is 2 * 2, to multiply a number by 4, double the number twice.
Example:
What is 4 * 100?
Double 100 to get 200.
Double 200 to get 400.
Therefore, 4 * 100 = 400.
By doubling twice, we do the same as multiplying by 4.
Answer: In an ordinary year, if you were to count all the days in a calendar from January to December, you'd count 365 days. But approximately every four years, February has 29 days instead of 28. So, there are 366 days in the year. This is called a leap year.
Step-by-step explanation:
Distance swam in 5 minutes = 85.4 yards
Since, 1 min = 60 seconds and 1 yard = 0.91 meter
5 minutes =
seconds
85.4 yards =
meters
So, Distance swam in 300 seconds = 77.7 meters
Now, we will use unitary method to determine the distance swam in 70 seconds.
Distance swam in 1 second =
= 0.26 meter
So, Distance swam in 70 seconds = 
= 18.2 meters
Therefore, the swimmer took 70 seconds to cover the distance of 18.2 meters.