Melissa and Thomas both solved the same problem using different methods.
Melissa's method shows 12 as divisor, 1784 as dividend and 107 as quotient. The first row below 1784 has -12, the second row has 8, the third row has -0, the fourth row has 84, the fifth row has -84 and the last row has 0.
Thomas' method has two columns and four rows. First row, first column has 1784 minus 1200 and second column has 100. Second row, first column has 584 minus 480 and the second column has 40. Third row, first column has 104 minus 96 and second column has 8. Fourth row, first column has 8 and the second column is blank. Thomas' answer is 148 R8.
Who solved the problem incorrectly and where did they first make their mistake?
A.
Melissa because 12 × 7 is 74.
B.
Thomas because 12 × 40 is 400.
C.
Melissa because she did not subtract 12 from 17.
D.
Thomas because his answer has a remainder.
B. Thomas because 12 × 40 is 400.
The person who solved the problem incorrectly is Thomas, and he first made his mistake in the calculation 12 × 40, which should have been 480 instead of 400. Therefore, the correct answer is:
B. Thomas because 12 × 40 is 480.