Browse · MATH Print → jmc algebra junior Problem What is the sum of the seven smallest distinct positive integer multiples of 9? Solution — click to reveal We are asked to calculate 9+18+27+⋯+63. Factor out 9 and use the identity 1+2+3+⋯+n=2n(n+1) to find that 9+18+⋯+63=9(1+2+⋯+7)=9⋅27⋅8=252. Final answer 252 ← Previous problem Next problem →