NECO 2024 · Paper 1 · Q15

Arrange the fractions $\frac23, \frac35, \frac5{12}, \frac4{15}, \frac3{10}$ in ascending order of magnitude.

Worked solution (try it first)

The LCM of 3, 5, 12, 15 and 10 is 60, so write every fraction in sixtieths.
$\frac23 = \frac{40}{60}$ , $\frac35 = \frac{36}{60}$ , $\frac{5}{12} = \frac{25}{60}$ , $\frac{4}{15} = \frac{16}{60}$ and $\frac{3}{10} = \frac{18}{60}$ .
Order the tops, smallest first: 16, 18, 25, 36, 40.
So the order is $\frac{4}{15}, \frac{3}{10}, \frac{5}{12}, \frac35, \frac23$ , option A.