Question

The missing number is a two-digit number that makes a value that is more than 80 but less than 90.

65+

Answer 1

The missing number is 25.

Step-by-step explanation:

Let's solve the expression
`\(65 + \_\_\)`with the condition that the missing number is a two-digit number, and the sum is more than 80 but less than 90.

Let the missing two-digit number be represented by \(xy\), where \(x\) is the tens digit, and y is the units digit.

The given expression is 65 + xy.

We know that the sum should be more than 80 but less than 90, so we have the inequality:

`\[80 < 65 + xy < 90\]`

Now, substitute 65 + xy back into the inequality:

`\[80 < 65 + xy < 90\]`

`\[80 < 65 + 10x + y < 90\]`

Now, solve for x and y using the given conditions.

For the tens digit x:

`\[10x\]` should be greater than or equal to 15 (to make the sum more than 80).

`\[10x \geq 15\]`

`\[x \geq (15)/(10)\]`

`\[x \geq 1.5\]`

So, x must be 2 (as x is a digit).

For the units digit y:

y should be greater than or equal to 0 (since it's a digit).

So, the missing number is 25, and the expression 65 + 25 equals 90.

Therefore, the detailed solution is that the missing two-digit number is 25.

The probable question can be: If the missing number is a two-digit number that makes a value more than 80 but less than 90 in the expression
`\(65 + \_\_\)`, what is the missing number?