Question

Mary's 3 hamsters each eat three-eighths of cup of grain a day, if she has 6 and 3/4 cups of grain, how many days will the grain last?

Answer 1

Answer:

6 days

Step-by-step explanation:

Each hamster eat $\frac{3}{8}$ of a cup of grain a day.

So in one day, the three hamsters eat:

$3*(\frac{3}{8} )=\frac{3*3}{8} =\frac{9}{8}$ cups

And since we know that Mary has 6$\frac{3}{4}$ cups of grain.

We need to convert this quantity into a fraction:

$6\frac{3}{4}=\frac{6*4+3}{4}=\frac{27}{4}$

she has $\frac{27}{4}$ cups of grain.

To find how many days the grain will last, we need to divide the total amount of grain she has ($\frac{27}{4}$ cups) by the amount that the three hamsters eat together in one day ($\frac{9}{8}$ cups):

$\frac{27}{4}$ ÷ $\frac{9}{8}$

and we use the rule to divide fractions:

$\frac{x}{y}$ ÷ $\frac{z}{w} =\frac{x*w}{y*z}$

this way we get:

$\frac{27}{4}$ ÷ $\frac{9}{8}$ $=\frac{27*8}{4*9}=\frac{216}{36}=6$

the grain will last 6 days

Answer 2

Hello!

3/8 times 3 equals 9/8 which is also 1 1/8. If you multiply 3/4 by two (numerator and denominator) then you will get 6/8. And if you multiply 9/8( I just find it easier with 9/8) by 6 you will get 54/8. And the grain will last for 6.75 days.

I may be wrong let me know.
Hope this helps!