Penjelasan dengan langkah-langkah:

barisan lama

n = 10

U₁ = a = 2

b = 3

un = a + (n - 1)

U₁₀ = 2 + (10 - 1)3

U₁₀ = 2 + 27

U₁₀ = 29

Sn = n/2 [ a + Un ]

S₁₀ = 10/2 [ 2 + 29 ]

S₁₀ = 5 ( 31 )

S₁₀ = 55

barisan baru

beda deret baru

b baru = b/(k + 1)

b baru = 3/(5 + 1)

b baru = 3/6

b baru = 1/2

U₁ = a = 2

beda (b) = 1/2

Un = 29

Un = a + (n - 1)b

29 = 2 + (n - 1)(1/2)

29 = 2 + n/2 - 1/2

29 = 4/2 + n/2 - 1/2

29 = n/2 + 3/2

29 = (n + 3)/2

2 x 29 = n + 3

58 = n + 3

n = 58 - 3

n = 55

Sn = n/2 [ a + Un ]

S₅₅ = 55/2 [ 2 + 29)

S₅₅ = 55/2 ( 31 )

S₅₅ = 852,5

jumlah bilangan yg disisipkan

= S₅₅ - S₁₀

= 852,5 - 55

= 797,5