Advertisements
Advertisements
Question
If a and b vary inversely to other, then find the values of p, q, r ; x, y, z and l, m, n.
| a | 2 | y | 6 | 10 |
| b | x | 12.5 | 15 | z |
Advertisements
Solution
If a and b vary inversely to other.
i.e. ab = k ...(Constant)
For table,
| a | 2 | y | 6 | 10 |
| b | x | 12.5 | 15 | z |
If a = 6 and b = 15
Then, a × b = 6 × 15 = 90
⇒ k = 90
When a = 2 and b = x, then
ab = k
⇒ 2 × x = 90
⇒ x = `90/2` = 45
When a = y and b = 12.5, then
ab = k
∴ y × 12.5 = 90
⇒ y = `90/12.5` = 7.2
When a = 10 and b = z then
ab = k
⇒ 10 × z = 90
⇒ r = `90/10` = 9
APPEARS IN
RELATED QUESTIONS
Rehman is making a wheel using spokes. He wants to fix equal spokes in such a way that the angles between any pair of consecutive spokes are equal. Help him by completing the following table:
| Number of spokes | 4 | 6 | 8 | 10 | 12 |
| Angle between a pair of consecutive spokes |
90° | 60° | ... | ... | ... |
- Are the number of spokes and the angles formed between the pairs of consecutive spokes in inverse proportion?
- Calculate the angle between a pair of consecutive spokes on a wheel with 15 spokes.
- How many spokes would be needed if the angle between a pair of consecutive spokes is 40°?
A batch of bottles was packed in 25 boxes with 12 bottles in each box. If the same batch is packed using 20 bottles in each box, how many boxes would be filled?
In a hostel of 50 girls, there are food provisions for 40 days. If 30 more girls join the hostel, how long will these provisions last?
If x and y vary inversely as other and x = 3 when y = 8, find y when x = 4 .
Five workers take 12 days to weed a field. How many days would 6 workers take? How many would 15 take?
The stock of grain in a government warehouse lasts 30 days for 4000 people. How many days will it last for 6000 people?
A printer, prints a book of 300 pages at the rate of 30 pages per minute. Then, how long will it take to print the same book if the speed of the printer is 25 pages per minute?
When two quantities are related in such a manner that if one increases and the other decreases, then they always vary inversely.
If x varies inversely as y and when x = 6, y = 8, then for x = 8 the value of y is 10.
If x varies inversely as y and y = 60 when x = 1.5. Find x. when y = 4.5.
