1. what number divided by 4 1/5 is of 100?

420

Step-by-step explanation:

Let the number be x

x / (4 1/5 ) = 100

x / (21/5 ) = 100

             x = 100 * (21 / 5) = 20 * 21 = 420

if x decreases by 4 then y increases by 10

step-by-step explanation:

30 miles

step-by-step explanation:

we know that 60 seconds equals 1 minute and 60 minutes 1 hour

44 ft       60 sec     60 min     158400   ft

  *   *   =

1 sec       1 min       1 hour         hour

we know that there are 5280 ft per mile

158400   ft       1 mile         30 miles

  *   =

1   hour               5280 ft     1 hour

so in 1 hour   it can travel 30 miles