In Crosby's model collection, 5/16 of the models are trains and 7/16 of the models are cars. What part of Crosby's model collection is trains and cars?

3/4.

Step-by-step explanation:

5/16 + 7/16

= (5+7)/16

= 12/16

= 3/4.

blue marble is 15 times out of 50 = 15/50 reduces to 3/10

landing on tails is 24 out of 50 = 24/50 reduces to 12/25

to find the probability of both multiply together:

3/10 x 12/25 = 3 x 12 / 10 x 25 = 36/250

if you multiplied the numerator and denominator by 10 you get 360/2500.

the answer is 360/2500

sorry, i can't understand your question. will later if you describe more clearly!

: )