# Thread: how do i work this out?

1. ## how do i work this out?

each cat will eat 3/4 of a tin of food every day

paul is going to be away for 7 days

what is the least number of tins needed to feed 2 cats

2. Originally Posted by starslacker
each cat will eat 3/4 of a tin of food every day

paul is going to be away for 7 days

what is the least number of tins needed to feed 2 cats

one cat eats $\displaystyle \frac {3}{4}$ tins of food per day

so two cats will eat $\displaystyle 2 \times \frac {3}{4} = \frac {3}{2}$ tins of food per day

so for 7 days, the cats will eat $\displaystyle 7 \times \frac {3}{2} = 10 \frac {1}{2}$ tins of food

so need need to have at least 11 tins of food

3. Originally Posted by starslacker
each cat will eat 3/4 of a tin of food every day

paul is going to be away for 7 days

what is the least number of tins needed to feed 2 cats
only one cat can have 7*3/4=51/4 in 7 days such that 2 cat can have 2*51/4=101/4tins in seven days

4. Originally Posted by asurekha1970
only one cat can have 7*3/4=51/4 in 7 days such that 2 cat can have 2*51/4=101/4tins in seven days
No, because $\displaystyle (7)(\frac{3}{4}) = \frac{21}{4}$ and not $\displaystyle \frac{51}{4}$

5. Originally Posted by starslacker
each cat will eat 3/4 of a tin of food every day

paul is going to be away for 7 days

what is the least number of tins needed to feed 2 cats
1 cat eats 3/4th of a tin per day

==> 1 cat eats 0.75 tins per day

==> 2 cats eat 0.75 * 2 = 1.5 tins per day

Mahurshi Akilla
==> For 7 days, 1.5 tins/day * 7 days = 1.5 * 7 tins = 10.5 tins = 10 1/2 tins

6. Originally Posted by janvdl
No, because $\displaystyle (7)(\frac{3}{4}) = \frac{21}{4}$ and not $\displaystyle \frac{51}{4}$
This is why I hate the $\displaystyle 7 \frac{3}{4}$ notation for $\displaystyle \frac{31}{4}$. The notation ought to be retired.

-Dan

7. Originally Posted by topsquark
This is why I hate the $\displaystyle 7 \frac{3}{4}$ notation for $\displaystyle \frac{31}{4}$. The notation ought to be retired.

-Dan
completely agree with you. but it was ot notation that messed asurekha1970 up here, he simply made an error