Question

find the sum of integers which are divisible by 2 and 3 from 1 to 50

Answer 1

sum of integers which are divisible by 6 must be subtracted from sum of integers which are divisible by 2&3 because 6 is the least common multiple of 2&3 hence their multiples get repeated so they must be subtracted .
hope this one helps you

Answer 2

So there are 8 integers from 1 to 50 which are divisible by 2and3
Hence, n=8
a=6
a2=12
a3=18
d=a2-a1
=12-6=6
S8=n/2[2a+(n-1)d]
=8/2[2(6)+(8-1)6]
=4[12+(7)6]
=4[12+42]
=4[54]
=216
Hence,the sum of integers divisible by 2&3 from 1to50 is 216