(40+x)/2=60
40 +x = 120
x = 80
check :
40+80 = 120
120/2 = 60
so his second round needs to be 80 mph
To find the answer to that, you have to see how many numbers are between 13 and 31. There are 18 numbers between 13 and 31. Divide 18 by 2 and you will get the number halfway. 9 is halfway between 13 and 31. So, add 9 to 13 and you get 22.
The answer is 22.
Hope I helped
940% because 47 divided by 5 is 9.4.
After I explain the procedure in full detail, you'll be able to generate
your own work. Here it is.
To find the greatest common factor of two numbers:
1). List all of the factors of the first number.
2). List all of the factors of the second number.
3). Scan both lists, and find factors that are on BOTH lists.
These are the COMMON factors. Write them down in a short list.
4). Scan the short list. Find the biggest number on it.
That's the Greatest Common Factor.
OK, I'll go through the first one in your picture . . . 24 and 42 :
1). Factors of 24: <em>1, 2, 3,</em> 4,<em> 6,</em> 8, 12, 24
2). Factors of 42: <em>1, 2, 3, 6,</em> 7, 14, 21, 42
3). Short list: <em>1, 2, 3, 6</em>
4). Biggest number on the short list:<em> <u>6</u> </em>
I would say you have a probability of 1/4 to pick a 3 in the first round and 1/3 in the second round
1/4 plus 1/3 = 7/12
