Maths Question.... PLEASE HELP!!?

Question

After 25% of a bill has been paid, $80 still remains to be paid. How much was the bill?

Please answer and tell me how u worked it out !!!

Answer 1

80 / .25 = 320 (which was paid)

4 X 320 = 1280  :)

Answer 2

80 / .75 = 106.66666 - 80 = 26.66

25% of the bills is $26.67

$80 still remain

Total $106.67

Answer 3

let total be b

then  b= 1/4*b+80

3/4*b=80

b=320/3

Answer 4

$80 - 75% of the bill remains unpaid

$26.67 - 25% of the bill has been paid

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$106.67 - Total (100%)

Answer 5

0.75*bill=80

bill = 80/0.75

=$106.67  (rounded)