find the sum of all natural numbers between 1 to 200 which are multiples of 5
Answers
Answered by
4
Answer:
3900
Step-by-step explanation:
AP formed : 5 , 10 , 15 , 20 , 25 ...... 195
a = 5
d = 5
an = 195
an = a + (n-1)(d)
195 = 5 + (n-1)(5)
195 = 5 + 5n -5
195 = 5n
n = 39
Sn = n/2 [ 2a + (n-1)(d)]
Sn = 39/2 [ 2(5) + (39-1)(5)]
Sn = 39/2 [ 10 + 190 ]
Sn = 39/2 × 200
Sn = 3900
Similar questions