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Jack
10-10-2013, 11:05 AM
How can we find the multiples of 4 between 278 and 679, inclusive?

miranda
10-10-2013, 11:06 AM
This can be solved using arithmetic sequences. We know that the nth term of an arithmetic sequence is given by the following formula:
a_{n}= a_{1} +(n-1)d, where a_{1} is the first term of the sequence (in our case is 280 since is the first multiple of 4 starting from 278) and d is the common difference of the progression (in our case the difference equals 4). The last term of the sequence is the number 676 which is the greater multiple of 4 less or equal than 679.
Therefore
676=280 +(n-1)4
4n=676-280+4
4n=400
n=100

Jack
10-10-2013, 11:06 AM
Thanks miranda!