John is 5 years older than Don and 3 years younger than Dave. If the total sum of their age is 79 how old is Don?
Let's assume Don's age to be x years.
John is 5 years older than Don, so John's age is x + 5 years.
Dave is 3 years older than John, so Dave's age is x + 5 + 3 = x + 8 years.
The sum of all their ages is x + (x + 5) + (x + 8) = 79
Simplifying the above equation, we get 3x + 13 = 79
Subtracting 13 from both sides, we get 3x = 66
Dividing both sides by 3, we get x = 22
Therefore, Don is 22 years old. Answer: \boxed{22}.
A motorcycle was sold at 20% discount.
If the motorcycle was sold for 4000, what was the original price?
Let's denote Don's age as "x".
According to the given information, John is 5 years older than Don. Therefore, John's age is (x + 5).
Additionally, John is 3 years younger than Dave. So, Dave's age is (x + 5 + 3) = (x + 8).
The total sum of their ages is 79. Therefore, we can write the equation:
x + (x + 5) + (x + 8) = 79
Combining like terms:
3x + 13 = 79
Subtracting 13 from both sides of the equation:
3x = 66
Dividing both sides of the equation by 3:
x = 22
Therefore, Don is 22 years old.
To determine Don's age, we can use algebraic expressions and equations. Let's assign variables to the three individuals:
Let D represent Don's age.
Since John is 5 years older than Don, John's age is D + 5.
Since John is 3 years younger than Dave, Dave's age is (D + 5) + 3, which simplifies to D + 8.
According to the given information, the total sum of their ages is 79, which can be expressed as:
D + (D + 5) + (D + 8) = 79.
To solve the equation, we combine like terms:
3D + 13 = 79.
Then, we isolate the variable:
3D = 79 - 13,
3D = 66.
Finally, we solve for D by dividing both sides of the equation by 3:
D = 66 / 3,
D = 22.
Therefore, Don is 22 years old.