Sum of all naturl no less than 200 that are divisible neither by 3nor by 5 is?

• Ans will be 10732
  (1+2+……….+200)-{(3+6+…..+198)+(5+10+…………+200)-(15+30+……………..195)}
  [as 15,30,45…….195 is terms are taken twice for 3 as well as 5,so have to subtract from their summation ]
  =(20100)-{6633+4100-1365}
  =20100-9368
  =10732
  
• 11 years agoHelpfull: Yes(32) No(2)
• 3,6,......198
  66*(3+198)/2=6633
  5,10,....200
  40*(5+200)/2=4100
  1,2,3....200
  =20100
  20100-4100-6633=9367
• 11 years agoHelpfull: Yes(4) No(9)
• number of numbers from 3 to 198 are 198/3=66
  thats why its 66*(3+198)/2
• 11 years agoHelpfull: Yes(3) No(3)
• (1+2+3+4+5+........+200)-(3+6+9+......+198)-(5+10+15+20+.....+200)=(200/2(200+1))-(60/2(3+198))-(40/2(5+200))=20100-6030-4100=9970
• 11 years agoHelpfull: Yes(1) No(1)
• but some numbers are common like-
  15,30,45,75,.....
  so, 2 times we can't subtract
• 11 years agoHelpfull: Yes(1) No(0)
• why everyone took a last no. is 200 while here is written it should be less than 200
• 11 years agoHelpfull: Yes(1) No(0)
• @vinod why 66?
  
• 11 years agoHelpfull: Yes(0) No(0)
• (1+200)*100-(15+195)*13/2=20100-1430=18670
• 11 years agoHelpfull: Yes(0) No(0)