Step-by-step explanation:
1. We need to find the value of 8.1 × 10³ − 2.4 × 10² in standard form.
We can also write its as :
8.1 × 10³ − 2.4 × 10²
81000 − 240
Standard form = 80760
2.
Amy's weight = 40 kg
Blood comprises 8% of the weight of a human.
Weight of her blood,
[tex]W=8\%\ of\ 40\\\\=\dfrac{8}{100}\times 40\\\\=3.2\ kg[/tex]
So, the weight of her blood is equal to 3.2 kg.
