Answer:
The actual speed of the car is either 57 mph or 63 mph
Step-by-step explanation:
Given as :
The measured speed o the car = 60 mph
The percentage error in speedometer = 5 %
Let The actual speed of car = x mph
Now, percentage error = 
× 100
So, 
= 
or, × 60 = x - 60
Or, 3 = x - 60
∴ x = 63 mph
Hence The actual speed of the car is either 57 mph or 63 mph . Answer
Answer:
12
Step-by-step explanation:
36 divided but 3 is 12 so x=12
A radioactive atmosphere around the area and an expensive, hard time cleaning everything up.
Answer:
18
Step-by-step explanation:
A two-digit number (xy) will have the value 10x+y. The sum of its digits is x+y.
You want ...
10x +y = 2(x +y)
1 ≤ x ≤ 9
0 ≤ y ≤ 9
The equation can be simplified to ...
8x = y
The only single-digit values for x and y that satisfy the requirements are ...
x = 1, y = 8
The two-digit number of interest is 18.
_____
<em>Check</em>
Its sum of digits is 1+8 = 9. 2×9 = 18.
_____
<em>Comment on the relationship in the problem</em>
Many of us learned our multiplication tables for 9s by remembering that the sum of digits of 9n was 9, and that the leading digit of the product was n-1.
