Try this solution:
Answer: 6 & 4.5 (m-per-h)
Step-by-step explanation:
- The basic formula used in this task is S=V*t, where S - distance, V - speed, t - time.
- the downstream speed is: V+Vc, where V - the speed of the boat in still water, Vc - the speed of the current.
- the upstream speed is: V-Vc.
- according to the described above the distance for downstream is S1=(V+Vc)*t1, where t1=10; the distance for upstream is S2=(V-Vc)*t2, where t2=70.
- for whole travel down- and upstream: S=S1+S2.
- Using these it is possible to make up the system of the equations:

V - the speed of the boat in still water - 6 miles per hour, Vc - the speed of the current - 4.5 miles per hour. All the details for the system of the equations are in the attachment.
Can't see the answer choices but Nicola is wrong. 16 * (12/8) = 24>16
Let
x-----------> <span>the first number
y-----------> </span><span>the second number
we know that
x*y=x-----------> y=x/x----------> y=1
and x+y=y------> x=y-y---------> x=0
the answer is
</span> the first number is 0
the second number is 1<span>
</span>
Answer:
y=x+100
Step-by-step explanation:
Answer:

Step-by-step explanation:
Number of blue marbles = 8
Total number of marbles = 16+8+7+1=32
