What is the sum of all multiples of 2 and all multiples of 3 from 1 to 50, inclusive?

50, inclusive?

first I didn’t understood why we took 25\times26 for 2 then 51\times8 for 3 and 54\times4 for 6 (okay I got the 6 part but 3 and 2 part I didn’t get it 51 is sum for 3 (like pair sum) and 25 is number of pairs but why 26 ??

Im sorry if I didn’t explained the question correctly I’m aloot confused also

my solution was 24\times52+\frac{52}{2} +(51\times8)-(54\times4)

What’s the sum of all multiples of 2 from 1 to 50, inclusive?

wait i made a mistake it was 12*52 and the ans I got 650…which I come to think of it he got the same and tho still confused about 25*26

What confuses you about the 25 \times 26 part?

i mean like how did they got 25*26 now 25 is like total no of multiples if I’m not mistaken(also I just started my gre prep soo if I’m doing something wrong or anything related and also if can have advice for gre please give )

just wanted to know was there anything different way that they wrote like why think of 26*25 but not like write the whole formula thing

Different approaches to the same problem. They used (total number of multiples) \times median. Using the formula is absolutely OK.

understood and fair enough

well also understood my mistake in calculation so thank you for your time alooot