The volume of balloon at  is
  is  .
.
Further explanation:
Charles’s law:
This law describes volume-temperature relationship of gases at constant amount of gas and pressure. According to this law, volume occupied by a fixed amount of a gas is directly proportional to its absolute temperature, provided pressure and amount of gas is kept constant.
Mathematical expression of Charles’s law:

Here,
V is volume occupied by the fixed quantity of gas.
T is temperature of gas.
The relationship can also be expressed as follows:
 [P and n are constant]
                                                 [P and n are constant]
Or it can also be expressed as follows:
 ...... (1)
                                                                           ...... (1)
Here,
  is initial volume of gas.
 is initial volume of gas.
  is final volume of gas.
 is final volume of gas.
  is initial temperature of gas.
is initial temperature of gas.
  is final temperature of gas.
 is final temperature of gas.
Rearrange equation (1) for  .
 .
 ...... (2)
                                                                           ...... (2)
The value of  can be calculated as follows:
 can be calculated as follows:

The value of  can be calculated as follows:
 can be calculated as follows:

Substitute 296.15 K for  , 319.15 K for
, 319.15 K for  and 535 mL for
 and 535 mL for  in equation (2).
 in equation (2).

Therefore final volume of balloon comes out to be 576.5 mL.
Learn more:
1. Law of conservation of matter states: brainly.com/question/2190120
2. Calculation of volume of gas: brainly.com/question/3636135
Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: Ideal gas equation
Keywords: Charles’s law, volume, temperature, pressure, volume-temperature relationship, absolute temperature, 576.5 mL, 296.15 K, 319.15 K, 535 mL, T2, T1, V1, V2, 296.15 K, 319.15 K.