Question

Please help with this problem sum , photo attached Thank you.

Answer 1

Let G, B and Y denotes the number of green, blue and yellow marbles.

Given that:

`\begin{gathered} G+B+Y=694 \\ B=3Y \\ B=G+90 \end{gathered}`

From this,

`Y=(B)/(3),G=B-90`

Substitute the vlaues of Y and G into the equation G+B+Y=694.

`\begin{gathered} B-90+B+(B)/(3)=694 \\ (7B)/(3)-90=694 \\ (7B)/(3)=784 \\ B=(784\cdot3)/(7) \\ =336 \end{gathered}`

Keith had 336 blue marbles.