java code

$1-$ A simple light switch works by changing states between on and off. Assume a boolean variable called isLightOn already exists and has been declared. Write a piece of code that reassigns isLightOn to its opposite value.

$2-$ In a system monitoring water quality, sensors measure pH level and turbidity to ensure safety. Given unsigned int variables pHLevel and turbidity, write an expression that evaluates to true if pHLevel is less than $1$ unit away from $7$ and turbidity is lower than $3.$ Assign the result of this expression to the variable isSafe that has already been declared.

$3-$ At an amusement park, tickets are sold at a discounted rate to visitors less than $16$ years of age, ones with more than $65,$ or ones that have paid a premium membership beforehand.

Given the variables int age and boolean hasMembership, write an expression that evaluates to true if the condition for a discount applies and assigns it to the variable discount, which has already been declared.