We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.
 
+0  
 
0
741
5
avatar+1112 

How many multiples of 8 are between 100 and 500?

 Jan 9, 2018
 #1
avatar+101870 
+1

[ 500  -  100 ]    /  8    -    1   =

 

400 /  8    -   1 =

 

50  -  1   =

 

49 multiples   "between"

 

 

cool cool cool

 Jan 9, 2018
 #2
avatar+1112 
0

sorry the problem is more sorry

 

How many different integers between 100 and 500 are multiples of either 6, 8,or both?

 Jan 9, 2018
 #3
avatar+101870 
+1

Multiples  of  8  =  

 

[500 - 100 ] /  8  -   1  =  50  -  1   =  49  between

 

Multiples of 6  =

 

[ 500 - 100 ] / 6  -  1   =  66 between

 

The LCD  for 6, 8  is 24....we must subtract the multiples of 24 between 100  and 500 from the above total

 

[ 500 - 100] / 24  =  16 between 

 

So.....the total multiples of 6, 8 (or both) between 100 and 500  =

 

49 + 66  -  16   =

 

99

 

 

cool cool cool

 Jan 9, 2018
 #4
avatar
+2

These are simply the number of terms in Arithmetic Series:

Number of terms =[ Last term - First term] / Common diffrence + 1

N =[496 - 104] / 8 + 1

N=[ 392] / 8 + 1

N= 49 + 1

N = 50 - multiples of 8 between 100 and 500

 

N =[ 498 - 102] / 6 + 1

N =[ 396 ] / 6 + 1

N= 66 + 1

N = 67 - multiples of 6 between 100 and 500

Total = 50 + 67 =117 - multiples of 6 and 8 between 100 and 500.

However, 6 and 8 have an LCM of 24.Therefore, multiples of 24 between 100 and 500 are

N = 16 - multiples of 24 between 100 and 500 which have been counted TWICE!. So the number of integers that are multiples of 6 and 8, or both, between 100 and 500 is:

117 - 16 = 101 Integers

 Jan 9, 2018
 #5
avatar+28074 
0

I'm in agreement with Guest#4 on this one!

 Jan 9, 2018

11 Online Users