Some pieces of apple and pear were sold respectively at a fruit parlor.
On Day 1, 50% of the number of the whole apple, 40% of the number of the whole pear sold.
On Day 2, remaining apples and pears were sold.
All pears were sold.
As for the apple, only the same number was sold as pear sold on Day 1 and 42 remained.
As for the total number of apple and pear sold on Day 2, 18 decreased from the total number of two fruits sold on Day 1.
Find the each number of apple and pear in this parlor first.
Answer
Apple : 180 pieces, Pear : 120 pieces
Solution
Each number of apple and pear first in the parlor is set to A and P respectively.
The number sold in Day1 is A × 0.5 apples and P × 0.4 pears.
The number sold of pear in Day2 is P × 0.6.
The number sold of apple in Day 2 is P × 0.4.
As 42 apples remained, A × 0,5 - P × 0.4 = 42.
Furthermore A × 0.5 - P × 0.6 = 18.
Thus P × 0.2 = 42 - 18 = 24.
P = 24 / 0.2 = 120.
P × 0.4 = 120 × 0.4 = 48
A × 0.5 = 48 + 42 = 90
Therefore A = 90 / 0.5= 180.
