Acyclist rode at an average speed of 10 mph for 15 miles. how long was the ride? a. 1.5 hours b. 10 hours c. 15 hours d. 150 hours

If the cyclist rode at an average speed of 10mph for 15 miles...

we can solve by dividing the distance by the speed to get time using the equation...

Δspeed = Δdistance / Δtime

Δtime = Δdistance / Δspeed

Δtime = 15 miles / 10 mph = 1.5 hours

The answer would be 1.5 hours
15 miles times 1 hour becomes 15 divided by 10 since 10 mph is how much the cyclist rode in an hour. Hope this helped.

Answer : option a) 84explanation :

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.

#2- the hno3 has a h+ ion and the naoh has an oh- ion