Arithmetic part: (1,4,7,\ldots) → (a_n=1+(n-1)3=3n-2)
Geometric part: (5,10,20,\ldots) → (b_n=5\cdot 2^{n-1})
8th term of A.G. sequence: [ t_8 = a_8\cdot b_8 = (3\cdot8-2)\cdot 5\cdot 2^{7} = 22\cdot 5\cdot 128 = 14080 ]
Answer: (14080)
Arithmetic part: (1,4,7,\ldots) → (a_n=1+(n-1)3=3n-2)
Geometric part: (5,10,20,\ldots) → (b_n=5\cdot 2^{n-1})
8th term of A.G. sequence: [ t_8 = a_8\cdot b_8 = (3\cdot8-2)\cdot 5\cdot 2^{7} = 22\cdot 5\cdot 128 = 14080 ]
Answer: (14080)