ALGEBRA K5

 The sum of four consecutive numbers which are multiples of 6 is 204. Find the 4th number.

 

Solution

 

Let the numbers be as shown in the table below

 

1st number	2nd number	3rd number	4th number	TOTAL
n	n+6	n+12	n+18	204

 

Then, n + (n+6) + (n+12) + (n+18) = 204

 

4n + 6+12+18= 204

 

4n + 36 = 204

 

4n = 204 – 36

 

4n = 168 

 

4n = 168

4      4

 

n = 42

 

4th number = n + 18

 

                   = 42 + 18

 

                   = 60

 

Hence the 4th number is 60

 

TRY THIS………………….. 

 

The sum of four consecutive numbers which are multiples of 7 is 406. Find the 4th number