Numbers which are multiple of 2 = 600
Numbers which are multiple of 3 = 400
Numbers which are multiple of 5 = 240
Total = 1240
Common multiples:
Numbers which are multiple of 6 = 200
Numbers which are multiple of 15 = 80
Numbers which are multiple of 10 = 120
Total = 400
Numbers co-prime to 6 or 15 = 1200 - (1240-400) =360
Since either is asked: Add the multiples of 30 = 40
Numbers co-prime to either 6 or 15 = 360+40 = 400
@Puys: Bhai log man ni lag raha tha aapke bina..Isliye aa gaya...Ab pakka bye bye
For 6, we've to remove every multiple of 2,3dude can u tell me y we have to remove every multiple of 3,5 for 8
1200(1-1/2)(1-1/3)=400
For 8, we've to remove every multiple of 3,5
1200(1-1/3)(1-1/5)=640
Coprime to both 6 and 15:
1200(1-1/2)(1-1/3)(1-1/5)=320.
Total: 400+640-320=720.
general form is taken when the difference of the nos in the given sequence are in a.p...it suits perfectly for tat particular type of questionh T c Sayshey, what is meant by general term of an AP or GP or HP ?
can anyone explain clearly how the general term isforget tat.. jus take the simple general formula as an^2+bn+c
(n^2 - n + 2)/2....just coping it from fb...
whenever the common difference is an AP, try to fit in a square.dude.. an^2+bn+c is a general formula right... can the same be used for any sequence of this form..?
Let the nth term be an^2+bn+c
extrapolate to find the 0th term of the series. It would be 3.
So, c=3
Put n=1
a+b+3=3; a+b=0
put n=2
4a+2b+3=5
4a+2b=2
2a=2=>a=1, b=-1
The nth term is n^2-n+3