Contemporary Math

Question

You read online that a 15 ft by 20 ft brick patio would cost about $2,275 to have professionally installed. Estimate the cost of having a 12 by 26 ft brick patio installed.

Round your answer to the nearest dollar.

Answer 1

15 by 20 cost $2275

how much does 12 by 26 cost?

15x20 = 300

12x26 = 314 >300, so cost is a little more than $2275

set the ratios equal

x/314 =2275/300 = 91/12

x/157 = 91/6

x = 157(91)/6 = 2381.1666...

= about $2381.17 for 12 by 16

= about $2381 rounded to nearest dollar

or calculate the cost per square foot

2275/15x20 = 2275/300 = $75.8333...

for an extra 14 square feet (314-300) it costs an extra 14x7.58

= about $106.12

2275+106.12 = $2381.12 which is close to a more accurate 2381.17, just 5 cents off

but it's the same answer when rounded to nearest dollar: $2381