By how much can wearing a helmet when riding a bicycle reduce the risk of head injury?

a.
85 percent

b.
10 percent

c.
15 percent

d.
40 percent

Wearing a helmet when riding a bicycle can reduce 85% the risk of a head injury. So the answer is A.

delegated (sometimes called enumerated or expressed) powers are specifically granted to the federal government in article i, section 8 of the constitution. this includes the power to coin money, to regulate commerce, to declare war, to raise and maintain armed forces, and to establish a post office.