8 apples and 10 oranges weigh 5 kg. 12 apples and 20 oranges weigh 9 kg. What is the weight (in kg, rounded off to the nearest integer) of 15 apples and 24 oranges?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 11.
Let the weight of one apple be x kg and one orange be y kg.
According to the given question,
8x + 10y = 5 ...(i)
12x + 20y = 9 ...(ii)
Multiplying equation (i) by 2,
⇒ 16x + 20y = 10 ...(iii)
Subtractiong equation (ii) from equation (iii),
⇒ 4x = 1
⇒ x = 1/4
Now, 8(1/4) + 10y = 5
⇒ 10y = 3
⇒ y = 3/10
So, 15x + 24y = 15(1/4) + 24(3/10)
⇒ 3.75 + 7.2 = 10.95 ≈ 11