7. John is cooking cupcakes. The recipe calls for 3 3/10 cups of flour. He accidentally put in 3 5/8 cups of flour. How many extra cups did he put in?(1 point)Responses

1. 132/145 cups

2. 3 5/8 cups

3. 6 37/40 cups

4. 13/40 cups is .4 the correct answer

1 answer

To find the number of extra cups of flour John put in, we need to subtract the correct amount (3 3/10 cups) from the amount he actually put in (3 5/8 cups).

To compare these two fractions, we need to have the same denominator. Let's convert the fraction 3 3/10 to an improper fraction with a denominator of 8:

3 3/10 = (3 * 10 + 3)/10 = 33/10

Now we can subtract:

3 5/8 - 33/10

To subtract fractions, we need a common denominator. The least common multiple of 8 and 10 is 40, so let's convert both fractions to have a denominator of 40:

(3 5/8) * (5/5) = 19/8 * 5/5 = 95/40
33/10 * (4/4) = 132/40

Now we can subtract:

95/40 - 132/40 = (95 - 132)/40 = -37/40

Since the result is negative, it means that John put in 37/40 cups LESS than he was supposed to. Therefore, the correct answer is:

4. 13/40 cups.