[Question]: John found that the average of 15 numbers is 40. If 10 is added to each number then the mean of the numbers is?
[Options]: A)50, B)45, C)65, D)78, E)64
[Solution]: 
First, Let's find the sum of the 15 numbers.
Since the average of the 15 numbers is 40, the sum of the 15 numbers is 15 * 40 = 600.
Next, let's add 10 to each number.
If we add 10 to each number, the sum of the numbers will increase by 10 * 15 = 150.
Then, let's find the new average.
The new sum of the numbers is 600 + 150 = 750.
Since there are still 15 numbers, the new average is 750 / 15 = 50.
Therefore, the mean of the numbers after adding 10 to each number is 50.
Answer: A


[Question]: If a / b = 3/4 and 8a + 5b = 22,then find the value of a.
[Options]: A)1/2, B)3/2, C)5/2, D)4/2, E)7/2
[Solution]: 
Let's think step by step. 
First, let's solve the equation a/b = 3/4 for a. We can do this by cross-multiplying:
4a = 3b
Next, let's substitute this value of a into the second equation 8a + 5b = 22:
8(3b/4) + 5b = 22
Multiplying through by 4 to get rid of the fraction:
24b + 20b = 88
Combining like terms:
44b = 88
Dividing both sides by 44:
b = 2
Now, let's substitute this value of b back into the equation 4a = 3b:
4a = 3(2)
4a = 6
Dividing both sides by 4:
a = 6/4
Simplifying:
a = 3/2
Therefore, the value of a is 3/2. 
Answer: B


[Question]: A person is traveling at 20 km/hr and reached his destiny in 2.5 hr then find the distance?
[Options]: A)53 km, B)55 km, C)52 km, D)60 km, E)50 km
[Solution]: 
Let's think step by step. 
Given:
Speed = 20 km/hr
Time = 2.5 hr
To find the distance, we can use the formula:
Distance = Speed x Time
Substituting the given values:
Distance = 20 km/hr x 2.5 hr
Calculating:
Distance = 50 km
Therefore, the distance is 50 km.
Answer: E



[Question]: How many keystrokes are needed to type the numbers from 1 to 500?
[Options]: A)1156, B)1392, C)1480, D)1562, E)1788
[Solution]: 
Let's think step by step.
For the numbers from 1 to 9, 1 keystroke is needed for each number. There are 9 numbers from 1 to 9, so 9 keystrokes are needed.
For the numbers from 10 to 99, 2 keystrokes are needed for each number. There are 90 numbers from 10 to 99, so 90 * 2 = 180 keystrokes are needed.
For the numbers from 100 to 500, 3 keystrokes are needed for each number. There are 401 numbers from 100 to 500, so 401 * 3 = 1203 keystrokes are needed.
Adding up all the keystrokes, we get 9 + 180 + 1203 = 1392 keystrokes.
Therefore, the 1392 keystrokes are needed to type.
Answer: B


[Question]: {}
[Options]: {}
[Solution]: 
Let's think step by step.
