<span>To subtract 7 from 13 you use the fact that 13 is one ten plus three units, i.e. 13 = 10 + 3. then you can subtract 7 from 10 which is 3, and then add the 3 other 3 units to get 3 + 3 = 6. In this way, you have subtracted 7 from 13 using the fact that 13 is one ten plus 3 units.</span><span>
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6 0

3 years ago

Train X is traveling at a constant speed of 30 miles per hour and Train Y is traveling at a constant speed of 40 miles per hour.

topjm [15]

Answer:

3.5 hours

Step-by-step explanation:

Speed of train X=30 mph

Speed of train Y=40 mph

Relative speed When the two trains travelling in same direction

Relative speed=40-30=10 mph

Total distance =25+10=35 miles

We have to find the time when train Y is 10 miles ahead of train X.

We know that

Time= $\frac{Distance}{Relative\;speed}$

Using the formula

Then, we get

Time= $\frac{35}{10}=3.5 hours$

Hence, it will be 3.5 hours until train Y is 10 miles ahead of train X.

7 0

3 years ago

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