A sales representative notes that in a particular week he drove 1350 km and used 120 L of petrol. His sales patre (in another vehicle) drove 940 km and used 88 L of petrol. Express their petrol usages as a rate in the form
kilometres: 100 L

9514 1404 393

Step-by-step explanation:

If u represents the desired usage rate, then the proportion is ...

  km/liters = ...

  u/100 = 1350/120

  u = 100(1350/120) = 1125 . . . . km/100 L — first vehicle

and ...

  u/100 = 940/88

  u = 100(940/88) = 1068.2 . . . . km/100 L — second vehicle

3. parallelogram

step-by-step explanation:

we turn each of our sides into direction vectors

ab=b-a=(3 - 7, 1 - 0) = (-4, 1)

bc=c-b=(1,6)

cd=d-c=(4,-1)

da=a-d=(-1,-6)

we see how the opposite sides have negated direction vectors; this is characteristic of a parallelogram.   we have congruent sides ab=cd and bc=da with unequal lengths because 1^2+6^2 is different from (-4)^2+1^2.   so it's not a square or a rhombus.  

we check the dot product of direction vectors of adjacent sides.   we have

ab dot bc = -4(1) + 1(6) = 2

that's not zero so the sides are not perpendicular.   we've ruled out rectangle.

the direction vectors indicate two pairs of congruent parallel sides, so we choose parallelogram over trapezoid.