A person's heart beats approximately 10^5 times each day. A person lives for approximately 81 years.
(a) Work out an estimate for the number of times a person's heart beats in their lifetime
Give your answer in standard form correct to 2 significant figures.​

You are making a battery for a science project. you have copper wire for your first electrode. you need to choose a conductor, a second electrode, and a device to plug into your battery. you have already chosen a lemon conductor. complete each statement below about the options that include a lemon conductor.

Fa bus driver leaves her first stop by 7: 00 a.m., her route will take less than 37 minutes. if she leaves after 7: 00 a.m., she estimates that the same route will take no less than 42 minutes. which inequality represents the time it takes to drive the route, r?

Which steps could be part of the process in algebraically solving the system of equations, y+5x=x^2+10 and y=4x-10