Question
A boat can travel 80 km downstream in 8 hours, and it
can travel the same distance upstream in 10 hours. What is the speed of the boat in still water?Solution
Let the speed of the boat in still water be x km/h, and the speed of the stream be y km/h. Downstream speed = x + y Upstream speed = x - y We know: Time downstream = Distance / Speed = 80 / (x + y) = 8, so x + y = 10 Time upstream = Distance / Speed = 80 / (x - y) = 10, so x - y = 8 Now, solve these two equations: x + y = 10 x - y = 8 Add the two equations: 2x = 18 ⇒ x = 9 km/h So, the speed of the boat in still water is 9 km/h. Correct Option: c) 9 km/h
Select the combination of numbers that when placed sequentially in the blanks of the given series will complete the series.
p q _ s _ u v _ x _...
Select the combination of letters that when sequentially placed in the blanks of the given letter series will complete the series.
_ m _ n _ n o ...
Select the combination of numbers that when placed sequentially in the blanks of the given series will complete the series.
C _ R _ _ N D _ _ _ T...
________ is a commonly used graphic format for the Web.
If all the letters of the word ‘PROPOSAL’ are replaced by their immediately preceding letter in alphabetical series, then how many pairs of letters ...
Which one of the following will come in third place when arranged in Alphabetical order?
Refer to the given number, symbol series and answer the question that follows. Counting to be done from left to right only. All numbers are single-dig...
Select the combination of letters that when sequentially placed in the blanks of the given letter series will complete the series.
l _ m m _ _...
Which element is exactly in the middle of third vowel from the left end and eighth symbol from the right end of the given arrangement?
Select the option that is related to the fifth number in the same way as the second number is related to first number and the third number is related to...
Relevant for Exams:
