Answer:
1.5 h
Explanation:
We know that distance travelled (d) equals rate of travel (r) times time (t) spent in travel. In symbols,
d = rt or rt =d
When Leah starts, Raul is already 30 min (0.5 h) ahead.
So, let t time for Leah and t + 0.5 be the time for Raul.
For Raul: 3(t+0.5) = d
For Leah: 4t = d
When Leah catches up with Raul, both will have travelled the same distance. So,
3(t+0.5) = 4t Remove parentheses
3t + 1.5 = 4t Subtract 3t from each side
t = 1.5 h
It takes Leah 1.5 h to catch up with Raul.
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<em>Check:
</em>
Distance travelled by Raul = 3 × (1.5 + 0.5) = 3 × 2 = 6 mi
Distance travelled by Leah = 4 × 1.5 = 6 mi
These two have different denominators, so you find the least common multiple. This problem goes to be 2/8+5/8, which equals 7/8。
Answer:
Step-by-step explanation:
x*y = 490
x + y = 49
x = 49 - y
y*(49 - y ) = 490
49y - y^2 = 490
0 = y^2 - 49y + 490
This does factor (oddly). It doesn't look like it, but it does.
(y - 35) (y - 14) = 0
y - 35 = 0
y = 35
y - 14 = 0
y = 14
x = 49 - y
Let y = 14
x = 49 - 14
x = 35
x = 49 - y
let y = 35
x = 49 - 35
y = 14
Solutions
(35,14)
(14,35) Both solutions are valid.
Answer:
Explanation:
The <em>possible values of r</em>, the correlation coefficient of a sequence of values, are -1 ≤ r ≤ 1.
This is, r cannot be either less than - 1 or greater than 1.
A correlation coefficient r = -0.1 denotes a very weak negative correlation. A correlation coefficient r = - 0.75 means a strong negative correlation. A correlation coefficient r = 0.5 indicates a moderate positive correlation. A value of r = 1.2 is not possible: r can neve be greater than 1.