Answer:
<h3>t = 15d</h3>
Step-by-step explanation:
You must first know that 1 week = 7days
If Sophie practices the piano 105 minutes in 1 week, this can be expressed as;
105 minutes = 7days
to calculate the total time t that she practices for any number of days, d, we will say;
t minutes = d days.
Solving both expression;
105 minutes = 7days
t minutes = d days.
Cross multiply;
7 * t = 105 * d
7t = 105d
Divide both sides by 7;
7t/7 = 105d/7
t = 15d
Hence a proportional equation for t in terms of d that matches the context is expressed as t = 15d
487 rounded to the nearest ten is 490......because 487 is closer to 490 then it is to 480.
Answer:
2 hours
Step-by-step explanation:
Let x mph be the speed of motorboat in still water and y mph be the speed of current.
A raft and a motorboat simultaneously leave from the same point and move down the river, then speeds down the river are:
motorboat = x + y mph
raft = y mph
In two hours they will cover:
motorboat = 2(x+y) miles
raft = 2y miles
After 2 hours the motorboat turns around and starts moving towards the raft (against the current), so its speed is now x - y mph.
Let t be the time they move towards each other. In t hours, they cover
motorboat = t(x - y) miles
raft = ty miles
The distance from the starting point to the turning point is the same as the sum of the distances the raft covers and the motorboat covers after turning around, so
Answer:
18
Step-by-step explanation: