The serial number on a bill consists of a letter followed by eight digits and then a letter. How many serial numbers are possible, giving the following conditions (a) letters and digits cannot be repeated (b) letters and digits can be repeated (c) the letters are nonrepeated consonants and the digits can be repeated ( let y be a consonant)

i believe it is c.y = 9x

rise over run. 9 units up over 1 unit right or 9/1

replace   with   27   and simplify.

10 , 27 , 10 , 70 , 10 , 35 , 10 , 48

step-by-step explanation:

t= half of the arc subtended by t.

r= half of the arc subtended by r.  

t+r= half of the arc subtended by t + half of the arc subtended by r= half of 360=180

step-by-step explanation: