The calendar obviously has an integral number of years and months in 400 years. If it has an integral number of weeks, then it will repeat itself after that time. The rules of the calendar eliminate a leap year in 3 out of the four century years, so there are 97 leap years in 400 years. The number of excess days of the week in 400 years can be found by ...
(303·365) mod 7 + (97·366) mod 7 = (2·1 + 6·2) mod 7 = 14 mod 7 = 0
Thus, there are also an integral number of weeks in 400 years.
The first day of the week is the same at the start of every 400-year interval, so the calendar repeats every 400 years.
Answer:
2400 in^3
Step-by-step explanation:
Tyler asks for a fish tank for his birthday. The task he wants is a rectangular prism 20 inches long, 10 inches wide, and 12 inches tall. How much water will the fish tank hold?
the capacity of the tank can be determined by calculating the volume of the tank
volume of a prism = length x width x height
20 x 10 x 12 = 2400 in^3
you cannot multiply any of the numbers above by another to get 12, the factors of 12 would be 1,2,3,4,6,12 1x12= 12 2x6=12 4x3=12
Perimeter of a rectangle = 2 (length + breadth)
or, 56 = 2(2.5 breadth + breadth)
or, 56 = 7*breadth
breadth = 56*7 = 8 cm
length = 2.5*8 = 20 cm
Let the x ml of water be mixed with 237 ml of ammonia whose strength is 100%, in order to create a mixture of 75% strength.
The equation required to solve this will be:
237/(237+x)=75/100
solving for x we get:
237/(237+x)=3/4
237×4=3(237+x)
948=711+3x
3x+711=948
3x=948-711
3x=237
x=237/3
x=79 ml
therefore the amount of water to be added will be 79 ml
