Those are awfully small apple pies.
Area = pi * r^2
A = 3.14 * 5^2
A = 78.5 square cm.
1.5 / 78.5 = $0.019 per square cm
A = 3.14 * 10^2
A = 314 sq. cm
314 * 0.019 = $5.97
An apple pie 10 cm in diameter costs $1.50. Then, an apple pie 20 cm in diameter should cost
a. $3.00
b. $4.00
c. $4.50
d. $6.00
e. $8.00
please answer and explain
2 answers
Since cost usually varies with the area
and the area is proportional to the square of the corresponding sides, the area would be 4 times as large, thus the cost would be 4($1.5) or $6.00
( ratio of sides = 2:1
so ratio of areas = 2^2 : 1^2 = 4 : 1
ratio of costs = 4 : 1 )
and the area is proportional to the square of the corresponding sides, the area would be 4 times as large, thus the cost would be 4($1.5) or $6.00
( ratio of sides = 2:1
so ratio of areas = 2^2 : 1^2 = 4 : 1
ratio of costs = 4 : 1 )
1 answer