1.) The speed of a stream is 3mph. A boat travels 10 miles upstream in the same it takes to travel 16 miles downstream. What is the speed of the boat in still water?
2.)Sally can paint a room in 3 hours while it takes Steve 6 hours to paint the same room. How long would it take them to paint the room if they worked together?
3.)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 35 cm when the weight is 4kg, what is the distance when the weight is 6 kg?
4.) If z varies inversely as w, and z =4 when w=6, find z when w=3.
5.)In a certain fraction, the denominator is 7 less than the numerator. If 1 is added to both the numerator and the denominator, the resulting fraction is equal to 12/5. Find the original fraction.
I'm having a lot of trouble with these, please help, thanks so much!
2.)Sally can paint a room in 3 hours while it takes Steve 6 hours to paint the same room. How long would it take them to paint the room if they worked together?
3.)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 35 cm when the weight is 4kg, what is the distance when the weight is 6 kg?
4.) If z varies inversely as w, and z =4 when w=6, find z when w=3.
5.)In a certain fraction, the denominator is 7 less than the numerator. If 1 is added to both the numerator and the denominator, the resulting fraction is equal to 12/5. Find the original fraction.
I'm having a lot of trouble with these, please help, thanks so much!
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TRICKY ANSWERS
1.) The speed of a stream is 3mph. A boat travels 10 miles upstream in the same it takes to travel 16 miles downstream.
The speed of the boat in still water = (16 + 10) / 2 = 13 mph
2.)Sally can paint a room in 3 hours while it takes Steve 6 hours to paint the same room.
If they worked together, they will take 3*6/(3+ 6) hrs = 2 hrs
3.)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 35 cm when the weight is 4kg, the distance when the weight is 6 kg is 35*6 / 4 cm = 52.5 cm
4.) If z varies inversely as w, and z =4 when w=6,
when w=3, z = 4*6/3 = 8
5.)In a certain fraction, the denominator is 7 less than the numerator. If 1 is added to both the numerator and the denominator, the resulting fraction is equal to 12/5.
Original fraction is (12 + 1) /(5 + 1) = 13/6
1.) The speed of a stream is 3mph. A boat travels 10 miles upstream in the same it takes to travel 16 miles downstream.
The speed of the boat in still water = (16 + 10) / 2 = 13 mph
2.)Sally can paint a room in 3 hours while it takes Steve 6 hours to paint the same room.
If they worked together, they will take 3*6/(3+ 6) hrs = 2 hrs
3.)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 35 cm when the weight is 4kg, the distance when the weight is 6 kg is 35*6 / 4 cm = 52.5 cm
4.) If z varies inversely as w, and z =4 when w=6,
when w=3, z = 4*6/3 = 8
5.)In a certain fraction, the denominator is 7 less than the numerator. If 1 is added to both the numerator and the denominator, the resulting fraction is equal to 12/5.
Original fraction is (12 + 1) /(5 + 1) = 13/6