9 pencils cost $7.74
what would determine the cost of 6 pencils

$5.16

Step-by-step explanation:

Because you divided 7.74 by 9 equal 0.86. Then if you multiply 0.86 by 6 then you get 5.16.

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.