There are some tarts in a box. The tarts can be put into plates of 2 or 6 with no tarts leftover. When the tarts are put into plates of 10, there are short of 4 tarts on the last plate. If there are more than 30 tarts but less than 50 tarts, how many tarts are there in the box?
If tarts can be put into plates of 2 or 6 with no tarts leftover, the number of tarts is a multiple of 6 as 6 is a multiple of 2.

Multiples of 6 that are greater than 30 but less than 50: 30, 36, 42, 48

Multiples of 10 that are greater than 30 but less than 50: 30, 40, 50
Multiples of 10 (- 4) that are greater than 30 but less than 50: 26, 36, 46

Common number = 36

Number of tarts = 36

Answer(s): 36