Question

There is a bag with only red marbles and blue marbles.The probability of randomly choosing a red marble is 7/12.There are 84 marbles in total in the bag and each is equally likely to be chosen.Work out how many red marbles there must be.

Answer 1

84 ÷12= 7 common ratio

7×7 red marbles = 49 red marbles

Answer 2

Answer:

35 Red Marbles

Step-by-step explanation:

P (B) = 7/12

P (B) = ☐/84

7/12 = ☐/84

   = 12x7 = 84

   = 7 x 7 = ☐ = 49

= 7/12 = 49/84

49/84 = Number of Blue Marbles

84 - 49 = Number of Red Marbles

  = 35

So there will be 35 Red Marbles