**Solution:**

The multiples of 8 are 8, 16, 24, 32…

The series is in the form of AP, with the first term as 8 and the common difference as 8.

Therefore, a = 8

d = 8

S_{15} = ?

By the formula of the sum of n terms, we know,

S_{n} = n /2 [2a + (n – 1) d ]

S_{15} = 15/2 [2(8) + (15 – 1)8]

= 15/2[16 + (14)(8)]

= 15/2[16 + 112]

= 15(128)/2

= 15 × 64

= 960