Answer:
40 pieces are sold at original price,
45 pieces are sold at reduced price.
Step-by-step explanation:
Let us assume the number of pieces sold at original price = x
Now, the total number of pieces sold = 85
⇒ Number of pieces pieces sold at ( original price + reduced price) = 85
or, The number of pieces sold at reduced price
= 85 - Number of pieces sold at original price = 85 - x
1 piece sold at original price costed = $10.50
⇒ The cost of selling x pieces at original price = x ( Cost of 1 original piece)
= x ($10.50) = 10.50x
Also, 1 piece sold at reduced price costed = $10.50 - $3 = $7.50
⇒ The cost of selling (85 - x) pieces at-reduced price
= (85-x) ( Cost of 1 reduced price piece)
= (85-x) ($7.50) = 7.50 (85-x)
Now, the all pieces are sold at $757.50
⇒ 10.50 x + 7.50 (85-x) = $757.50
or, 10.50 x + 637.5 - 7.5x = 757.5
or, 3 x = 757.5 - 637.5 = 120
or, x = 120/3 = 40
or, x = 40
hence, 40 pieces are sold at original price,
(85 -x) = (85 - 40) = 45 pieces are sold at reduced price.
