Can you help me with this word problem?

Question

Jan had an average of 17.5 for 6 spelling tests. How many spelling must she get right in the next test, if she is to raise her score to eighteen??

Answer 1

ANSWER: 21

Figure Jan's necessary point total by multiplying desired average (18) by number of tests she will have taken at that point (7): 18 * 7 = 126

Then calculate Jan's current point total by multiplying her average (17.5) by the current number of tests taken (6): 17.5 * 6 = 105

Then subtract 126 from 105 to get the needed score on the next test: 126 - 105 = 21

Or, simply put: (18 * 7) - (17.5 * 6) = 21

Answer 2

21

Answer 3

Like he said. 21

17.5 x 6 = 105

18 x 7 = 126

126 - 105 = 21