Question

Find the sum of all natural puraber from 50 to 250 which are divisible
by 6 and Find
w
Find S,
Find t​

Answer 1

574

Question Bank Solutions6066

Concept Notes & Videos246

Time Tables23

Syllabus

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Sum

Find the sum of all members from 50 to 250 which divisible by 6 and find t13.

SOLUTION

The numbers between 50 to 250 which are divisible by 6 are

54, 60, 66 ....246

Here a = 54, d = 6 and tn = 246

tn = a + (n - 1) d

246 = 54 + (n - 1) (6)

246 - 54 = 6n - 6

192 = 6n - 6

192 + 6 = 6n

6n = 198

n = 198÷6

n = 33

Sn = n÷2[t1+tn]

S =33÷2[54+246]=

³³

33÷2[300]

S = 4950

³³

tn = a + (n - 1) d

t= 54 + (13 -1) (6)

¹³

= 54 + 12(6)

= 54 + 72

t = 126

¹³