Question

the answer should be 55
what's wrong in my solution
plz tell me ............​

Answer 1

2nd condition.

260 is not divisible by 40. You should have divided by 20.

260x+40y=10000

13x+2y=500 will be correct.

Answer 2

Let the weight of box A and B be x and y respectively

According to the first condition

150x +100y=10,000

3x+2y=200

3x=200-2y

$x = \frac{200 - 2y}{3} \: \: \: \: \: \: \: \: .....(1)$

According to the second condition

260x+40y=10,000

13x+2y=500 .......(2)

Substituting equation (1) in equation(2),we get

$13x + 2y = 500 \\ 13( \frac{200 - 2y}{3} ) +2 y = 500 \\ 2600 - 26y + 6y = 1500 \\ - 20y = 1500 - 2600 \\ - 20y = - 1100 \\ y = \frac{1100}{20} \\ y = 55$

Substituting the value of y in equation (1)

$x = \frac{200 - 2(55)}{3} \\ x = \frac{200 - 110}{3} \\ x = \frac{90}{3} \\ x = 30$