Answer:
there are twelve total combinations
Step-by-step explanation:
just by looking at the problem though,
ABCD
AB
AC
AD
BA
BC
BD
CA
CB
CD
DA
DB
DC
normally, because some of them are repeated, we need to get rid of some
AB
AC
AD
BC
BD
DC
since this is about passwords though, we need to keep all of the same twelve combinations because the order of the letters are important
Convert the decimal number to a fraction by placing the decimal number over power of ten. Since there are 3 numbers to the right of the decimal point, place the decimal number over 10^3 (1000). Then, add the whole number to the left decimal.
89 9/1000
2x3(S-+7)=6xS=7............
If 75% liked skating, then 25% did not
so 25% of what is 35
0.25x = 35
x = 35/0.25
x = 140...so there is a total of 140 students
75% of 140 =
0.75(140) = 105...so 105 students liked skating