Advertisements
Advertisements
Question
The variable x varies directly as y and x = 80 when y is 160. What is y when x is 64?
Advertisements
Solution
If x varies directly as y.
∴ `x/y = k` (constant) ...(i)
If x = 80 and y = 160
∴ `x/y = 80/160 = 1/2`
⇒ `k = 1/2`
When x = 64, then from equation (i),
`64/y = 1/2` ...[Putting the value of k]
⇒ y = 64 × 2 = 128
APPEARS IN
RELATED QUESTIONS
Complite the following table given that x varies directly as y .
| x | 2.5 | ... | ... | 15 |
| y | 5 | 8 | 12 | ... |
6 men can complete the electric fitting in a building in 7 days. How many days will it take if 21 men do the job?
8 men can do a piece of work in 9 days. In how many days will 6 men do it?
Every 3 months Tamilselvan deposits ₹ 5000 as savings in his bank account. In how many years he can save ₹ 1,50,000
Both x and y vary inversely with each other. When x is 10, y is 6, which of the following is not a possible pair of corresponding values of x and y?
A truck needs 54 litres of diesel for covering a distance of 297 km. The diesel required by the truck to cover a distance of 550 km is ______.
A car covers a distance in 40 minutes with an average speed of 60 km/h. What should be the average speed to cover the same distance in 25 minutes?
It is given that l varies directly as m. Find the constant of proportion (k), when l is 6 then m is 18.
Shabnam takes 20 minutes to reach her school if she goes at a speed of 6 km/h. If she wants to reach school in 24 minutes, what should be her speed?
Ms. Anita has to drive from Jhareda to Ganwari. She measures a distance of 3.5 cm between these villages on the map. What is the actual distance between the villages if the map scale is 1 cm = 10 km?
