Question

1} Find the sum of first 50 odd natural number
2} a=5 d=0 n =207 an=?

Answer 1

Hey....!! HERE IS YOUR ANSWER....!!!

1.) The sum is 

1+3+5+7+...........50 terms

Therefore the given series is in ARTHIMETIC PROGRESSION where a=1,d=2,n=50

sum is n/2(2a+(n-1)d)

BY SUBSTITUTING

25(2+98)

2500

SO THE SUM OF FIRST 50 ODD NUMBERS IS 2500......

2.) an = a+(n-1)d
= 5 + (207 -1) 0
= 5 + (206)0
= 5+0
= 5..... ANS.....

HOPE IT'S WILL HELP YOU A LOT....!!
@ujjwalusri