SG chevron_right Primary 5 chevron_right Number and Algebra

Hi, anyone could help me on this question? Thank You

SG chevron_right Primary 5 chevron_right Fractions

SG chevron_right Primary 5 chevron_right Number and Algebra

Pls help. Thks

SG chevron_right Primary 3 chevron_right Number and Algebra

SG chevron_right Primary 3 chevron_right Number and Algebra

some pupils took part in a contest, 15 of them won at least one medal each. 8 of them won a silver medal. 13 of them won a bronze medal. how many of them won both a silver and bronze medal