Richards bought a number of red roses and yellow roses on February 14th. Each red rose costs $9, and each yellow rose costs $14. If Richard spent a total of exactly $220, how many roses did Richard buy?
A. 16
B. 17
C. 19
D. 20
E. 21
The OA is D.
I solved this PS question writing an equation as follow,
9r + 14*(x - r) = 220, where r is the number of red roses and x is the total number of roses that Richard bought.
Then,
$$14x-5r=220\ \Rightarrow 14x=5\left(44+r\right)$$
That's mean x its a multiple of 5. Only option D satisfies that.
Is there a strategic approach to this PS question? Can any experts help, please? Thanks!
A. 16
B. 17
C. 19
D. 20
E. 21
The OA is D.
I solved this PS question writing an equation as follow,
9r + 14*(x - r) = 220, where r is the number of red roses and x is the total number of roses that Richard bought.
Then,
$$14x-5r=220\ \Rightarrow 14x=5\left(44+r\right)$$
That's mean x its a multiple of 5. Only option D satisfies that.
Is there a strategic approach to this PS question? Can any experts help, please? Thanks!















