Question

name:
monday
a number has the digits 2, 8 and 6. to the nearest 10, the number rounds to 830. what is the number?
find the difference between 600 and 453.
it takes luis 12 minutes to run a mile. how many minutes will it take him to run 3 miles?

Explanation:

First Sub - Question: Determine the number

Step1: Analyze the rounding rule

When rounding to the nearest 10, we look at the ones digit. If the ones digit is 5 or more, we round up; if it's less than 5, we round down. The rounded number is 830, so the original number is either 825 - 834 (but we only have digits 2, 8, 6). Let's consider the tens and hundreds place. The hundreds digit should be 8, the tens digit: since it rounds to 830, the tens digit before rounding could be 2 (if we round up) or 3 (if we round down, but we don't have 3 as a digit). Wait, the digits available are 2, 8, 6. Let's form the number. The number has digits 2, 8, 6. Let's assume it's a three - digit number. Let the number be \(826\). When we round \(826\) to the nearest 10, we look at the ones digit (6). Since \(6\geq5\), we round up the tens digit. \(2 + 1=3\), so \(826\) rounded to the nearest 10 is \(830\). Let's check other combinations. If we try \(862\), rounding to the nearest 10: the ones digit is 2, so we round down to \(860\), which is not 830. If we try \(286\), rounding to the nearest 10: ones digit 6, round up to \(290\), not 830. If we try \(268\), rounding to the nearest 10: ones digit 8, round up to \(270\), not 830. If we try \(628\), rounding to the nearest 10: ones digit 8, round up to \(630\), not 830. If we try \(682\), rounding to the nearest 10: ones digit 2, round down to \(680\), not 830. So the number is \(826\).

Step2: Verify the rounding

For \(826\), the ones digit is 6. Rounding to the nearest 10: we increase the tens digit by 1 (since \(6\geq5\)) and set the ones digit to 0. So \(2 + 1 = 3\), and the number becomes \(830\), which matches the given condition.

Step1: Recall the subtraction formula

The difference between two numbers \(a\) and \(b\) (where \(a>b\)) is given by \(a - b\). Here, \(a = 600\) and \(b = 453\).

Step2: Perform the subtraction

\(600-453=147\)

Step1: Recall the rate formula

If it takes \(t = 12\) minutes to run 1 mile, then to run \(n = 3\) miles, we use the formula \(Total\ time=n\times t\).

Step2: Calculate the total time

Substitute \(n = 3\) and \(t = 12\) into the formula: \(Total\ time=3\times12 = 36\) minutes.

Answer:

\(826\)

Second Sub - Question: Find the difference between 600 and 453