Three fourths times two is one and a half so if you add three fourths to that you will get two and one fourth.
If you multiply the fraction three-fourths by two you will get six-fourths. If you change that improper fraction to a mixed fraction you will get one and two-fourths. The two-fourths reduces to one-half. There fore three-fourths times two is one and a half.
Three eighths. Simple multiplication.
It is seven fourths which is one and three fourths as a mixed number.
The answer is 15 and 3 fourths. 21 times 3 equals 63 then you put the 4 from the three fourths underneath and reduce 63 fourths to 15 and three fourths. 4 divided by 63 is 15 with a remainder of 3 which leaves you with 15 and three fourths.
One fourth and three fourths gives you a whole gallon
1.75 + 1.75 = 3.5 One and three fourths plus one and three fourths is three and a half.