He takes 6 hours to stitch a single shirt and stitches 6/10 of a shirt in 1 hour.
The answer
the full question is
If A(x1, y1), B(x2, y2), C(x3, y3), and D(x4, y4) create two line segments, and AB ⊥ CD, what condition must be satisfied to establish that AB ⊥ CD?
Let A(x1, y1) and B(x2, y2) represent the first line, while C(x3, y3) and D(x4, y4) represent the second line.
The slope for the first line is given by m = (y2 - y1) / (x2 - x1).
For the second line, the slope is m' = (y4 - y3) / (x4 - x3).
The necessary condition to demonstrate that AB ⊥ CD is
(y2 - y1) * (y4 - y3)
m × m' = --------- × ------------ = -1
(x2 - x1) (y4 - y3)
Start by letting x represent the number of Sam's pencils. Then Sari has 3x (since she has three times as many)
Together they total 28 pencils:
x + 3x = 28
4x = 28 /:4 (divide both sides by 4)
x = 7
So Sam has 7 pencils.
Sari, having three times as many, has 7 * 3 = 21.[[TAG_8]]