If ²⁸C_r:²⁴C_r-4 =225:11, then find r.

The sum of two numbers is 58. the first number is 8 less than half the second number. let  c  represent the first number. let  drepresent the second number. which statements about solving for the two numbers are true? check all that apply.the equation    represents the sum of the two numbers.the equation    represents the sentence “the first number is 8 less than half the second number.”the equation    represents the relationship between the two numbers.the equation    represents the sum of the two numbers.the number  d  is 14.the number  c  is 44.the number  c  is 14.the number  d  is 44.

An advertising firm has an old computer that can prepare a whole mailing in 6 hours. with the of newer model the job is complete in 2 hours. how long would it take the newer model to do the job alone?

International calls require the use of a country code. many country codes a 3-digit numbers. country codes do not begin with a 0 or 1. there are no restrictions on the second and third digits. how many different 3-digit country codes are possible?