He bought if for $31.14 and this is 25% off the original price.
Let the original price be P.
25% of original price P = (25/100) P = 0.25P.
We have to take this off from P. = P - 0.25P = 0.75P
0.75P = 31.14
P = 31.14 / 0.75 = 41.52 Use your calculator.
Hence original price = $ 41. 52.