Answer:
1/250
Step-by-step explanation:
5^-3 × 2^-1
5^-3 = 1/5^3 = 1/125
2^-1 = 1/2^1 = 1/2
so 5^-3 × 2^-1 means 1/125 × 1/2
= 1/125 × 1/2
= 1/250
