Josefina lives near a duck pond. She wants to know how many ducks use the pond. She places leg bands on 12 ducks one day. A week later, she examines 20 ducks and finds that 3 of them have leg bands. About how many ducks use the pond? 80 29 160 50

80

Step-by-step explanation:

This is calculated as:

(Number of ducks with bands × Number of examined ducks)/ Number of ducks found with leg band

= Number of ducks with bands = 12 ducks

Number of examined ducks = 20 ducks

Number of ducks found with leg band = 3 ducks

Hence:

12 × 20/3

= 240/3

= 80 ducks

Therefore, 80 ducks used the ponds

d. bc = 12 and ef = 16

step-by-step explanation:

we are given that δabc : δdef such that .

also, it is given that

so, from the options, we need that .

a.

b.

c.  

d.

as, we can see that only option d gives the same ratio as i.e. .

hence, the possible lengths are bc = 12 and ef = 16.

step-by-step explanation:

first, eliminate the parenthesis:

3

x

+

2

−

4

x

second, group like terms:

3

x

−

4

x

+

2

third, combine like terms:

(

3

−

4

)

x

+

2

→

−

1

x

+

2

→

−

x

+

2