2007-08-14 05:04:37 · 4 answers · asked by mansur e 1 in Science & Mathematics ➔ Mathematics
A = sum of numbers divisible by 3
= 3+6+9+12+15+18+21+24+27+30+33.and so on
= 3 ( 1+2+3+4+5+6+7............+66 )
= 3 *66/2*(1+66)
= 3*33*67
= 6633
B = sum of numbers divisible by 5
= As above
= 5(1+2+3+4+..........+40)
= 5*40/2*(1+40)
= 5*20*41
= 4100
2007-08-15 14:06:25 · answer #1 · answered by brainy 4 · 0⤊ 0⤋
Numbers divisable by 3 are 3x(x=1,2,3,4......65,66)[since 3*67=201>200] and their sum =(3x+6x+9x+........+195x+198x)
=3(1+2+3+..........66)
just calculate (1+2+3+..........66) by the formula of a.p. series.
numbers divisable by 5:follow above process
2007-08-14 13:03:57 · answer #2 · answered by Kalyan 2 · 0⤊ 0⤋
why dont you do that its preaty tough.
2007-08-14 12:09:43 · answer #3 · answered by Bijeet 2 · 0⤊ 0⤋
a)6633
b)4100
2007-08-14 12:17:38 · answer #4 · answered by Devil's Advocate 2 · 0⤊ 0⤋