QUESTION

A bag with a total 10 balls contains x blue and y red balls. If the number of blue balls is four times the number of red, then write the two equations.${\text{A}}{\text{. x + y = 10,x = 4y}}${\text{B}}{\text{. x - y = 10,x = 4y}}${\text{C}}{\text{. xy = 10,x + 4y = 0}}$${\text{D}}{\text{.}}$ none of these

Hint: Since, the total number of balls in the bag is 10, here we have two types of balls (blue,red) so for finding the equations we assume numbers of balls as variables.

Complete step-by-step solution -
Given in the question, the total number of balls in the bag is 10.
Also, the number of blue balls = x.
Number of red balls = y.
Therefore, we can say that if the total number of balls in the bag is 10.
This implies that $x + y = 10 \to (1)$
Also, given in the question that the number of blue balls is four times the number of red balls.
Therefore, we can write that $x = 4y \to (2)$
Hence, the two equations are $x + y = 10 \to (1)$and $x = 4y \to (2)$.
So, the correct option is ${\text{A}}{\text{. x + y = 10,x = 4y}}$.

Note: Whenever such types of questions appear, always note down the values and conditions that are mentioned in the question. Using these details, form the equations and identify the correct option.