Math 117 Week Four Checkpoint Questions

  1. Solve. 4/3 +1/4 = 1/x

Ans: x=12/19

  1. Solve. 9/11v + 6/v = 1

Ans: v= 75/11

  1. Solve. 2/x+8 = 4/x

Is it 2/x + 8 = 4/x?

Ans: x= ¼

If it is 2/(x+8) = 4/x, then

Ans: x= -16

  1. Solve the equation for X. x-5/x+6 = x+5/x+3

Ans: x= -45/13

  1. Solve the equation for X. 4/x-2 + 3/x+2 = 5x/x^2-4

Ans: x= -1

  1. Solve.(answer may be either an integer or simplified fraction). 3 – a-5/a+3 = a^2 – 1/a+3

Ans: a = 5

(a=-3, discarded as we get denominator 0,which is meaningless)

  1. Solve (use a comma to separate answers as needed). (5a-4)= a+16/ a+1

Ans: a= 2 and -2.

  1. Jack usually mows his lawn in 7 hours. Marilyn can mow the same yard in 6 hours. How much time would it take for them to mow the lawn together? (answer can be in the form of an integer, proper fraction, or mixed number.)

Ans: 3 3/13 hrs

  1. The speed of a passenger train is 10 mph faster than the speed of a freight train. The passenger train travels 320 miles in the same time it takes the freight train to travel 270 miles. Find the speed of each train. Passenger train speed?______Freight train speed?______

Ans: 64mph and 54 mph

  1. A long distance trucker traveled 144 miles in one direction during a snow storm. The return trip in rainy weather was accomplished at double the speed and took 3 hours less time. Find the speed going. The speed going was ______mph.

Ans:24 mph

  1. ALREADY COMPLETE
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  3. 10CM^3 of a normal specimen of human blood contains 1.2 g of hemoglobin. How many grams does 28 cm^3 of the same blood contain?

Ans:3.36 g

  1. ALREADY COMPLETE
  2. ALREADY COMPLETE
  3. Hat sizes are determined by measuring the circumference of one’s head in either inches or centimeters. Use ration and proportion to complete the following table

Hat size / Head circumference (to nearest 1/5 inch) / Head circumference to nearest centimeter
7 1/8 / 22 2/5 / 57
6 7/8 / 21 3/5 / 55
  1. A sample of 127 firecrackers contained 4 duds. How many duds would you expect in a sample of 1905 firecrackers?

Ans:60

  1. X g 15 4 Y X Z F 6 H For the pair of similar triangles, find the value of X. (THE LETTERS ARE AT THE POINTS OF THE TRIANGLES. THE NUMBERS ARE PLACED CORRECTLY. )

Ans:22.5

  1. Find the variation constant and an equation of variation where Y varies directly as X and Y=24 when X=4. The variation constant is K=____.

Ans:6

  1. The number N of aluminum cans used each year varies directly as the number of people P using the cans. If 53 people use 14,681 cans in one year, how many cans are used ina city which has a population of 1,398,000?

Ans:387,246,000

  1. Hooke’s Law. The distance D when a spring is stretched by a hanging object varies directly as the weight W of the object. If the distance is 55 cm when the weight is 2 kg, what is the distance when the weight is 6 kg?

Ans:165 cm

  1. Find the variation constant and an equation of variation where Y varies inversely as X and Y =10 when X=16. The variation constant is ____.

Ans:160

  1. It takes 4 hrs for 9 cooks to prepare the food for a wedding rehearsal dinner. How long will it take 8 cooks to prepare the dinner? (a) What kind of variation applies to this situation? Inverse or direct? ______(b)Solve the problem.

Ans:4.5 hrs

Inverse variation

  1. The stopping distance D of a car after the brakes are applied varies directly as the square of the speed R. If a car traveling 70 mph can stop in 270 ft, how many feet will it take the same car to stop when it is travelling 30 mph?

Ans: 49.59 ft