When all of the whole numbers between 100 and 350 are written down, how many times does the digit 4 appear?

4 appears 55 times between 100 and 350

Step-by-step explanation:

First lets compute the number of times 4 appear from 100 to 200

104, 114, 124, 134, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 154, 164, 174, 184, 194

From 100 to 200: 4 appears 20 times 1

Using the same method as above:

From 200 to 300: 4 appears 20 times 2

From 300 to 350: 4 appears 15 times 3

304, 314, 324, 334, 340, 341, 342, 343, 344 ( 2 times ), 345, 346, 347, 348, 349

From eq 1, 2 and 3

From 200 to 350: 4 appears : 20 + 20 + 15 = 55 times

c.

step-by-step explanation:

she should of added 9^2 and 12^2. that is because it is a^2+b^2=c^2. c^2 is the hypotenuse and should always be bigger than the other two numbers. which is why she should of added 9 squared and 12 squared together instead of 15 squared.

2

step-by-step explanation: