80% of 20 is 80/100 x 20 = 16
So, kelly has used 16 stamps, and has 4 left
Answer:60$
Step-by-step explanation:
Answer:
n ≥ -17
Step-by-step explanation:
Writing a symbolic inequality, we get:
10 - 3n ≤ 61
Solve this for 3n by adding 3n to both sides of this equation:
10 ≤ 61 + 3n
Solve for n by subtracting 61 from both sides and then dividing all of the resulting terms by 3:
-51 ≤ 3n (divide both sides by 3):
-17 ≤ n, or
n ≥ -17
There are 10,000 total four-digit numbers (1000 through 9999).
Multiples of 2 end in 0, 2, 4, 6, and 8. There are 9*10*10*5 = 4500 four-digit multiples of 2.
Multiples of 5 end in 0 or 5. There are 9*10*10*2 = 1800 four-digit multiples of 5.
There is redundancy between the two sets of numbers, namely those that end in 0, which are both multiples of 2 and 5. There are 9*10*10*1 = 900 four-digit multiples of both 2 and 5.
Then there are 4500 + 1800 - 900 = 5400 total four-digit numbers that are either multiples of 2 or 5, which means the remaining 4600 numbers are neither multiples of 2 nor 5.
