There is a bag with only red marbles and blue marbles. The probability of randomly choosing a red marble is 3/10. There are 12 red marbles in the bag and each is equally likely to be chosen. Work out how many marbles in total there must be.

40

Step-by-step explanation:

Let x = total number of marbles

p(red) = (number of red marbles)/(total number of marbles)

3/10 = 12/x

3x = 120

x = 40

The total number of marbles is 40

10a^3+277a^2-132a-792

step-by-step explanation:

(2a+11)(5a-12)(foil)

=10a^2-24a+55a-132 =10a^2+31a-132

(10a^2+31a-132)(a+6)

=10a^3+60a^2+31a^2+186a^2-132a-792 =10a^3+277a^2-132a-792

i hope this is what you are looking for : )

the first option is the answer.