Advertisements
Advertisements
Question
A man completed a trip of 136 km in 8 hours. Some part of the trip was covered at 15 km/hr and the remaining at 18 km/hr. Find the part of the trip covered at 18 km/hr.
Advertisements
Solution
Total distance of the trip = 136 km
Let part of the trip covered at 18 km/hr = x km
∴ Distance of the trip covered at 15 km/hr = (136 - x)km
Time taken by the man to cover x km = `"Distance"/"speed" = "x"/18` hours
Time taken by the man to cover (136 - x) km = `(136 - "x")/15` hours
Time taken by the man to cover a trip of 136 km = 8 hours
`therefore "x"/18 + (136 - "x")/15 = 8`
`=> "x"/18 xx 90 + (136 - "x")/15 xx 90 = 8 xx 90`
....[Multiplying each term by 90 becuase L.C.M. of denominatorsn = 90]
⇒ 5x + 6 (136 - x) = 720
⇒ 5x + 816 - 6x = 720
⇒ 5x - 6x = 720 - 816
⇒ -x = -96
⇒ x = 96
∴ Part of the trip covered at 18 km/hr = 96 km
APPEARS IN
RELATED QUESTIONS
Solve the following equation:
15 + x = 5x + 3
Solve: `"2x"/3 - ("x" - 1)/6 + ("7x" - 1)/4 = 2 1/6` Hence, find the value of 'a', if `1/"a" + 5"x" = 8`
Fifteen less than 4 times a number is 9. Find the number.
A number decreased by 30 is the same as 14 decreased by 3 times the number; Find the number.
Three consecutive whole numbers are such that if they be divided by 5, 3 and 4 respectively; the sum of the quotients is 40. Find the numbers.
Solve: `(2"x")/3 - (3"x")/8 = 7/12`
Solve:
13(x − 4) - 3(x − 9) − 5(x + 4) = 0
After 12 years, I shall be 3 times as old as 1 was 4 years ago. Find my present age.
The sum of two numbers is 405 and their ratio is 8 : 7. Find the numbers.
Solve the following inequation
4x – 9 > – 33, where x is a negative integer
