Advertisements
Advertisements
प्रश्न
The variable x varies directly as y and x = 80 when y is 160. What is y when x is 64?
उत्तर
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
संबंधित प्रश्न
A loaded truck travels 14 km in 25 minutes. If the speed remains the same, how far can it travel in 5 hours?
In which of the following tables x and y vary directly?
(i)
| a | 7 | 9 | 13 | 21 | 25 |
| b | 21 | 27 | 39 | 63 | 75 |
(ii)
| a | 10 | 20 | 30 | 40 | 46 |
| b | 5 | 10 | 15 | 20 | 23 |
(iii)
| a | 2 | 3 | 4 | 5 | 6 |
| b | 6 | 9 | 12 | 17 | 20 |
(iv)
| a | 12 | 22 | 32 | 42 | 52 |
| b | 13 | 23 | 33 | 43 | 53 |
A and B can do a piece of work in 18 days; B and C in 24 days and A and C in 36 days. In what time can they do it, all working together?
If half a meter of cloth costs ₹ 15. Find the cost of `8 1/3` meters of the same cloth
If 45 persons can complete a work in 20 days, then the time taken by 75 persons will be ______ hours.
Devangi travels 50 m distance in 75 steps, then the distance travelled in 375 steps is ______ km.
It is given that l varies directly as m. Find the constant of proportion (k), when l is 6 then m is 18.
A car travels a distance of 225 km in 25 litres of petrol. How many litres of petrol will be required to cover a distance of 540 kilometres by this car?
The table shows the time four elevators take to travel various distances. Find which elevator is fastest and which is slowest.
| Distance (m) | Time (sec.) | |
| Elevator- A | 435 | 39 |
| Elevator- B | 448 | 28 |
| Elevator- C | 130 | 10 |
| Elevator- D | 85 | 5 |
How much distance will be travelled by elevators B and C separately in 140 sec? Who travelled more and by how much?
A recipe for a particular type of muffins requires 1 cup of milk and 1.5 cups of chocolates. Riya has 7.5 cups of chocolates. If she is using the recipe as a guide, how many cups of milk will she need to prepare muffins?
