Question

. Three water bottles X, Y and Z contain 920 mL of
water altogether. Bottle X contains twice as much
water as bottle Y. Bottle Z contains 20 mL less water
than bottle X. How much quantity of water is there
in bottle Z?​

Answer 1

Answer:

here is the solution.

there fore answer is z=320ml

Answer 2

Three water bottles X, Y and Z contain 920 mL of  water altogether. Bottle X contains twice as much  water as bottle Y. Bottle Z contains 20 mL less water than bottle X. Bottle Z has 356mL of water

Let bottle X contain x mL of water,

Let bottle Ycontain y mL of water,

Let bottle Zcontain z mL of water.

From the question, it is told that the three bottles, in total, contain 920 mL of water.

∴ (x + y + z) mL = 920 mL

→ x + y + z  =  920                                 ...(1)

Given that, bottle X contains twice as much water in bottle Y.

∴ x = 2y.                                                 ...(2)

And it is also mentioned that, bottle Z contains 20 mL less water  than bottle X.

∴ z = x - 20.                                            ...(3)

Putting the value of x = 2y from (2) in (3)

∴ z = x - 20 = 2y - 20.

So, z = 2y - 20                                       ...(4)

Putting the value of x = 2y (from 2) and z = 2y - 20 (from 4) in equation (1), we get,

2y + y + 2y - 20 = 920

⇒ 5y = 940

⇒ y = 188 mL

Putting the value of y = 180 in eqn (2), we get,

x = 2(188) = 376 mL

Also, putting the value of y = 188, in eqn (4), we get,

z = 2(188) - 20 = 376 - 20 = 356 mL

So, bottle X contains = x mL = 376 mL

Bottle Y contains = y mL = 188 mL

Bottle Z contains = z mL = 356 mL.

Thus bottle Z has 356 mL of water.