Question

Find the sum of all two digit natural number which when divided by 3

yields 1 as remainder.​

Answer 1

10+13+.....+96+97

an=a+(n-1)d

97=10+(n-1)3

90=3n

n=30

sn=n/2(2a+(n-1)d)

sn=15(20+57)

sn=1155

therefore the sum of all two digit natural number which when divided by 3, yields 1 as rremainder is 1155

hope this helps u.