Answer:
5
Step-by-step explanation:
Firstly, we know that the number of $10 bill is 1/10 of $1 and 1/5 times that of $5 bills.
We also know that the amount of $10 bills equal that of $1 bills and the total amount of bills we have is $225.
Now, let the amount of $10 be x. This means the amount of $1 bill is 10x and the amount of $5 bill is 5x.
Mathematically:
$10[x] + $1[10x] + $5[5x] = $225
$10x + $10x + $25x = $225
$45x = $225
x = $225/$45 = 5
This means she have only 5 $10 bills
Answer:
Orginal Speed is 135
Step-by-step explanation:
The ratio of final speed: original speed is
We know that 90 km is it final speed so, we set up a proportion
145 = -16 t² + 80 t +s
s = ?
v = v0 - at
0 = 80 - at
80 = at
s = 80 t - at²/2
s = 80 t - 80t/2
s = 40 t
Finally: 145 = -16 t² + 80 t + 40 t
16 t² - 120 t + 145 = 0
We will solve this quadratic equation:
t = [120 +√ ( (-120)²- 4 · 16 · 145 )] / 32
t = [120 + √ (14400 - 9280) ] / 32
t = (120 + 71.55) / 32 = 5.98 ≈ 6 s
Answer:D) 6 seconds
