SOLVE THESE PROBLEMS CORRECTLY TO BE MARKED BRAINLIEST! 1. Sophie wrote a two-digit number on the board. Max wrote the digi

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SOLVE THESE PROBLEMS CORRECTLY TO BE MARKED BRAINLIEST!

1. Sophie wrote a two-digit number on the board. Max wrote the digit 3 to the right of it and got a number that is bigger than the Sophie’s number by 372. What number did Sophie write on the board?

2. Some kids went on a bike ride. The ride was six hours long and the kids traveled 54 miles. For part of the ride they biked at a speed of 7 mph and for part of the ride they biked at a speed of 11 mph. For how long did they bike at the first speed, and for how long at the other speed?

3. I left Boston for Washington, DC, at 7:00 am. At first, my speed was 55 mph; then it was 75 mph. I traveled 630 miles in 10 hours. At what time did I begin to drive faster?

Thanks!

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Ngọc Diệp 3 years 2021-08-24T11:58:09+00:00 1 Answers 29 views 0

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  1. Eirian
    0
    2021-08-24T11:59:31+00:00
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    Answer: 1= 41

    2= 3 hours biking at the other speed.

    3= We began to drive at 75 mph at 1:00 p.m

    Step-by-step explanation:

    3= x/55 + (630 – x)/75 = 10


    75x + 55 * (630 – x) = 41,250 (4,125 as Lowest common multiple)


    75x + 34,650 – 55x = 41,250


    20x = 41,250 – 34,650 (Subtracting 34,650 at both sides)


    20x = 6,600


    x = 6,600/20


    x = 330 ⇒ 630 – x = 300


    Time we drove at 55 mph = 330/55 = 6 hours


    Time we drove at 75 mph = 300/75 = 4 hours


    We began to drive at 75 mph at 1:00 p.m. (7 am + 6 hours)

    hope this helps 🙂

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