I think it's 21/100 because I found the common denominator by multiplying by ten so I multiplied 1 times ten to get 10. Does that help?
E pi and F pi and (for third one) are correct answers
Answer:
the answer is 20
Step-by-step explanation:
The answer is 20. The rule of math, for this math problem, is that you do the multiplication first and then solve. Order of operations is "PEMDAS," which explained is by following these rules: Parentheses First.
Answer:
Yes
Step-by-step explanation:
For number 3 you answered them all correctly as well as number 4 and 5. Don't hesitate asking questions like these :D
<h3>Rate of the boat in still water is 70 km/hr and rate of the current is 15 km/hr</h3><h3><u>Solution:</u></h3>
Given that,
A motorboat travels 165 kilometers in 3 hours going upstream and 510 kilometers in 6 hours going downstream
Therefore,
Upstream distance = 165 km
Upstream time = 3 hours
<h3><u>Find upstream speed:</u></h3>

Thus upstream speed is 55 km per hour
Downstream distance = 510 km
Downstream time = 6 hours
<h3><u>Find downstream speed:</u></h3>

Thus downstream speed is 85 km per hour
<em><u>If the speed of a boat in still water is u km/hr and the speed of the stream is v km/hr, then</u></em>
Speed downstream = u + v km/hr
Speed upstream = u - v km/hr
Therefore,
u + v = 85 ----- eqn 1
u - v = 55 ----- eqn 2
Solve both
Add them
u + v + u - v = 85 + 55
2u = 140
u = 70
<em><u>Substitute u = 70 in eqn 1</u></em>
70 + v = 85
v = 85 - 70
v = 15
Thus rate of the boat in still water is 70 km/hr and rate of the current is 15 km/hr