Answer
The correct translation of the statement "twice 4 and 20 parrots" is $(2\cdot 4 + 20)$.
Work Step by Step
The petshop has "twice 4 and 20 parrots", which could possibly translate to:
$2(4 + 20)$ or $2\cdot 4 + 20$.
To determine which equation is true, let us evaluate both equations:
EQUATION 1: $2(4 + 20) = 8+40 = 48$
EQUATION 2: $2\cdot 4 + 20 = 8 + 20 = 28$
Hence, there could either be 48 or 28 parrots in the shop.
Now, according to the problem, the bird lover purchased $\frac{1}{7}$ of the birds. Apply that condition to equations 1 and 2:
Let x be the total number of parrots in the shop and y be the actual number of parrots bought.
EQUATION 1:
$y=\frac{1}{7}x, x = 48$
$y=\frac{1}{7}\cdot 48$
$y=6.8571$ birds
EQUATION 2:
$y=\frac{1}{7}x, x = 28$
$y=\frac{1}{7}\cdot 28$
$y=4$ birds
Since we are talking of birds, a whole number should be desired. Thus, the correct translation of the statement "twice 4 and 20 parrots" is $(2\cdot 4 + 20)$.