Fractions with Hours and Days

Question

So the question is:

The number of hours left in a day on Mars was $\frac{1}{4}$ on the number of hours that had already passed. How many hours were left in the day?

Day on Mars: $40$ hours.

I did $\frac{1}{4}\times40$ and got $10$. It seems a bit too simple of a solution, is this answer correct?

Is "$\frac 14$ on the number of hours passed " supposed to be "$\frac 14$ of the number of hours passed" or $\frac 14$ more than the number of hours (hence $\frac 54$ of the number of hours) passed? — Ross Millikan, Jan 09 '15 at 01:33

score 2 · Answer 1 · answered Jan 09 '15 at 01:30

2

No, your solution is not correct. Let $x$ be the number of hours that already passed during the day. The number of hours remaining would then be $\dfrac{x}{4}$. Since a day is $40$ hours, you have

$$x+\frac{x}{4}=40$$ Can you continue?

answered Jan 09 '15 at 01:30

Edward Jiang

3,670

Why did you put x/4? – John Jan 09 '15 at 01:37
Because it's $\frac{1}{4}$ of $x$. – Edward Jiang Jan 09 '15 at 01:38

Irrational Person · Answer 2 · 2015-01-09T01:44:19.457

1

The Solution

The number of hours left in a day on Mars was 1/4 on the number of hours that had already passed.

converts to $$x+\frac{x}{4} = 40$$

so

plug in and get

$$32+ \frac{32}{4} = 40$$

32 hours passed and there where 8 hours left.

edited Jan 09 '15 at 01:44

answered Jan 09 '15 at 01:38

Irrational Person

420

Fractions with Hours and Days

2 Answers2