There are 90 4-digit palindromes
<h3>What are palindromes?</h3>
Palindromes are numbers whose reverse is the same as the original number
<h3>How to determine the count of 4-digit palindromes</h3>
Since the digit is 4, then
- The first digit of the palindrome can be any of 1 to 9 (i.e. 9 digits)
- The second digit can be any of 0 - 9 (i.e. 10 digits)
- The third digit must be the second digit (i.e. 1 digit)
- The last digit must be the first digit (i.e. 1 digit)
So, the total number of digits is:

Evaluate the product

Hence, there are 90 4-digit palindromes.
Read more about numbers at:
brainly.com/question/251701
Answer:
22⁰
Step-by-step explanation:
By angle sum property :
x + 127 + 31 = 180⁰
x = 180 - 158
x = 22⁰
First, you add 5.34 to 21.8, which is 26.41. Then, you subtract 2.36 from 26.41, which is 24.5.
Answer:
A motor running at 75 revolutions per second.
Step-by-step explanation:
Given statement: A motor running at 4500 RPM, revolutions per minute.
⇒ In one minute , a motor running at 4500 revolutions.
Use conversion:

We have to calculate how many revolutions per second.
in 60 sec , a motor running at 4500 revolutions
then,
in 1 sec , a motor running at
revolutions.
Therefore, a motor running at 75 RPS, revolution per second.