Question

What operation do they use? Whats the total amount they collected.

Answer 1

What operation is used. Is a multiplicarion between irrational numbers.

What is the amount collected

It must be multiplied 15.5 x 3.98

Replace 15.5 = 15+ 0.5

3.98 = 4-0.02

then 15x 4 + 0.5x4 - 15x(0.02) - 0.5x(0.02)

Then result 60 + 2 - 0.30 - 0.01

62 - 0.31 = 61.69