Question

WORD PROBLEMS INVOLVING SIMULTANEOUS EQUATIONS:

The cost of a bottle of water is Rsx.
The cost of a bottle ofjuice is Rsy.
The total cost of 9 bottles of water and 3 bottles of juice is Rs 153.
The total cost of 6 bottles of water and 5 bottles of juice is Rs 147.
Find the cost of a bottle of water and the cost of a bottle of juice.

Answer 1

Explanation:

9x + 3y = 153

6x + 5y = 147

the first equation can be divided by 3 and then multiplied by 2. and from that we can subtract equation 2 :

9x + 3y = 153 | /3

3x + y = 51 | ×2

6x + 2y = 102

- 6x + 5y = 147

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0 -3y = -45

3y = 45

y = 15

3x + y = 51

3x + 15 = 51

3x = 36

x = 12

1 bottle of water costs Rs 12.

1 bottle of juice costs Rs 15.