Math Help!!!!!!!!!!!!!!?

Question

How can I xpress the in miles per hour:
1) 1 miles in 4 mins
2) 21,120 ft in 4 hours
Show work
ANOTHER PROBLEM:
hUMAN HAIR grows at a rate about .35mm per day. How much does it grow in 30 days?
Thanx

Answer 1

1) 1 miles in 4 mins

[(1 mile)/(4 min)] *[(60 min)(1 hr)]

(1/4)*(60/1) mph

(60/4) mph

15 mph


2) 21,120 ft in 4 hours

[(21120 ft)/(4 hr)]*[(1 mi)/(5280 ft)]

(21120/4)*(1/5280) mph

1 mph


hUMAN HAIR grows at a rate about .35mm per day. How much does it grow in 30 days?

.35 mm/day * 30 days = 10.5 mm

Answer 2

1) 1miles in 4 mins = 15 miles in 60 mins
2) 21120 ft in 4 hours = 5280 ft in 1 hour = 1 mile in 1 hour
35mm x 30 = 1050 mm

Answer 3

1) 1 miles in 4 mins = 1 mile/ 4 min
= 1 mile /(4 min/ (60 min/hour))
= 1 mile /((4/60)hr), cancel min
= 1 mile *(60/(4 hr)), or
= 60 miles / 4 hrs or
= 15 mph

2) 21,120 ft / 4 hours, there are 5280 ft in 1 mile or
(21,120 ft / (5280 ft/mile) )/ ( 4 hours) =
(21,120 ft / (5280 ft/mile) )/ ( 4 hours) =
(4 miles)/(4 hours) = 1 mph.

For your last problem, just muliply .35 mm/ day * 30 days, leaving you with .35*30 mm.

Always check your units.

Answer 4

1) 15 miles per hour
there are 15 four minute incrimants in an hour, so in an hour you would go 1 mile per incrimant (15*1=15)

2) 1 mile an hour
21,120 is exactly 4 miles and 4 miles in 4 hours is 1 mile in one hour.

3) .35(mm) * 30(days)= 10.5 mm

Answer 5

1) 1 mi/4 min X 60 min/1 hr = 15 mi/ 1 hr

2) 21120 ft/4 hr = 5280 ft/1 hr

5280 ft/1 hr X 1 mi/5280 ft = 1 mi/ 1 hr

3) 0.35 X 30 = 10.5 mm/month

Answer 6

You do miles divided by hours

1)times both by 15
15/60= 15 miles per hour

2)divide both by 4
5280 feet = 1 mile
1 mile per hour

3) .35*30=10.5mm

Answer 7

1. 4 min=4/60 hr=1/15 hr
so speed= 1mile/(1/15)hr = 15 miles per hour

2.speed=21120/4 ft/hr
=5280ft/hr
=1mph (since 1mile=5280ft)

3.Length of hair grows in one day=0.35mm
So,Length of hair grows in 30 days=30*0.35mm
=10.5mm