Question

If x varies directly as y and
1) x = 10 when y = 6, find y when
x = 35
2) x = 9 when y = 15, find x when
x = 11
3) x = 14 when y = 16, find y when x = 42
4) x = 22 when y = 12, find y when x = 11
5) x = 7 when y = 36, find y when x = 21

Answer 1

1. Y = 21
ok....
Do other with same method

Answer 2

Given:

x varies directly with y

To find:

The values of y for the given values of x

Solution:

We can find the solution by following the given process-

We know that x and y vary directly which means the value of y will increase/ decrease with an increase/ decrease in the value of x.

Using the unitary method, we can find the values.

1. x=10 when y=6

x:y=10:6=5:3

When x=35,

y=3×35/5

y=21

2. x=9 when y= 15

x:y=9:15=3:5

When x=11,

y=5×11/3

y= 18.3

3. x= 14 when y= 16

x:y=7:8

When x=42,

y=42×8/7

y=48

4. x= 22 when y= 12

x:y=11:6

When x=11,

y=11×6/11

y=6

5. x= 7 when y= 36

x:y=7:36

When x=21,

y=21×36/7=36×3

y=108

Therefore, the values of y for the given values of x are 21, 18.3, 48, 6, 108.