Find the sum of all multiples of 7 lying between 500 and 900
Answers
Answered by
0
Answer:
peeylyldyldulstatjs
Answered by
1
Answer:
39900
Step-by-step explanation:
Divisible by 7 between 500 and 900 is 504, 511, 518...........889, 896
a= 504
d=7
tn= 896
tn= a+(n-1)d
896=504+(n-1)7
896-504=(n-1)7
392= (n-1)7
392/7=n-1
56=n-1
n=57
Sn=n/2(2a+(n-1)d)
S57=57/2(2*504+56*7)
=57/2(1008+392)
=57/2(1400)
=57*700
S57 =39900
therefore the sum of all multiples of 7 between 500 and 900 is 39900
Similar questions