What the heck is this; I have a probability question?
I am completely thrown off by this question, it makes no sense to me.
16. If 8x + 5x + 2x + 4x = 114, the 5x + 3 =
A. 12 B. 25 C. 33 D. 47 E. 86
13. If r = 5 z then 15 z = 3 y, then r =
A. y B. 2 y C. 5 y D. 10 y E. 15 y
9. The city council has decided to add a 0.3% tax on motel and hotel rooms. If a traveler spends the night in a motel room that costs $55 before taxes, how much will the city receive in taxes from him?
A. 10 cents B. 11 cents C. 15 cents D. 17 cents E. 21 cents
14. If 300 jellybeans cost you x dollars. How many jellybeans can you purchase for 50 cents at the same rate?
A. 150/x B. 150x C. 6x D. 1500/x E. 600x
The answers are: 16) C 13) A 9) D 14) A, but I don't know why. Can someone explain?
Ask_me2010-01-12T03:43:00Z
Favorite Answer
It is really very simple. 16. sum them up. it would yield 19x=114 or x=6 now find out 5x + 3 = 5*6+3 = 30 +3 = 33 hence C
13. 15 z = 3 y means y= (15/3) z = 5 z, which is same as r thus r=y hence A
9. 0.3% of 55 dollars = 0.165 dollars. Since you cannot have a fractional cent, it would get rounded off to the next value = 17 cents (had the fraction been less than half cent, it would have been ignored)
Hence D
14. for x dollars you can get 300 jellybeans for 1 dollar you can get 300/x jellybeans for 50 cents you gat 300/2x = 150/x jellybeans hence A
Hope it helps. By the way where is the probability problem?
Solve for x: 19x = 114 , x = 6, then 5x + 3 = 30 + 3 = 33
13. If r = 5 z then 15 z = 3 y, then r =
If 15z = 3y then z = 3y/15 = y/5 So put y/5 in for z in the first equation: r = 5*y/5 = y
9. The city council has decided to add a 0.3% tax on motel and hotel rooms. If a traveler spends the night in a motel room that costs $55 before taxes, how much will the city receive in taxes from him? 0.003*55 = 0.165 dollars, probably rounded up to 17 cents since it is a tax.
14. If 300 jellybeans cost you x dollars. How many jellybeans can you purchase for 50 cents at the same rate? x / 300 = 0.50 / y Where y is the # of jelly beans and x the number of dollars. Solve for y: xy = (300)(0.5) xy = 150 y = 150 / x
With the 1st question, simply find x. Sum = 19x. If 19x = 114 then x = 6. So 5x + 3 = 33 Answer is C.
With 2nd question, if 5z = r, then 15z = 3r. But 15z = 3y. So r = y. Answer is A.
With 3rd question, if tax = 0.3% then $55 x 0.3% = 16.5 cents But it has to be rounded up (or down). In this case it is rounded up, so the tax is 17 cents. Answer is D.
With the 4th question, 300 jellybeans cost x dollars, so 1 bean costs x/300 dollars or x/3 cents. If one bean costs x/3 cents, then 50 cents will cost 50 times 3/x jellybeans, or 150/x beans. [you have to think in reverse] Answer is A.