. In a sale, there is twenty-five per cent off all prices. A chair costs £45 in the sale.
How much was it before the sale?

€60

Step-by-step explanation:

€45 = 75%

100% (original) = (100/75)

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.