Question

Colin paid $4 for 4 buns and 4 cakes. 3 buns cost as many as 2 cakes.What was the total cost of 5 buns and 5 cakes? (My teacher gave this to my class as a brainteaser. I'm Australian and I'm nowhere near the smartest in my class. My homework is due in 6 hours. I've been taking tutoring classes for atleast 6 years now, I'm in grade 5.)

Answer 1

4b+4c=4
3b = 2c, so substitute that into the first equation
4b+6b=4
10b=4
b=$0.40
3b= $1.20, so 2c=$1.20, and c=$0.60

Answer 2

If 4 buns and 4 cakes cost $4 ,then
1 buns and 1 cake costs $1
--> 4b + 4c = 4
b + c = 1

you want 5 buns + 5 cakes
= 5b + 5c
= 5(b+c)
= 5(1) = $5

The fact that 3 buns cost as much as 2 cakes is not needed and is simply a distraction.
It would matter only if you needed the actual cost of a bun and a cake, but that was not asked for.
Nice little question.


Olivia, most of the math tutors on here live in the US and Canada, so you posted at 1:47 am our time, which means most of them were probably asleep.
So you missed your 6 hour deadline. Keep the time difference in mind for next time