Answer:
12.496
Step-by-step explanation:
In a geometric series, the next number is equal to the previous number times the rate. Here, the first number is 10 and the rate is 1/5. Therefore,
a1 = 10
a2 = 10 * 1/5 =2
a3 = a2 * 1/5 = 2/5
a4 = a3 * 1/5 = 2/25
a5 = a4 * 1/5 = 2/125
Add these terms up to get 12.496 as our final answer