Bobby has 3 times as many model spaceships as his friend sylvester does. bobby has 21 spaceships. how many model spaceships does sylvester have?

Miranda is braiding her hair.then she will attach beads to the braid.she wants 1_3 of the beads to be red.if the greatest number of beads that will fit on the braid is 12,what other fractions could represent the part of the beads that are red?

Ateam of runners is needed to run a 1 2 -mile relay race. if each runner must run 1 4 mile, how many runners will be needed?

Use the given information to determine the exact trigonometric value.