Help to resolve my Kotlin code please

Question

fun shippingCost(amount: Double, international: Boolean): Double {

var cost: Double

if(international) {
if ((amount * 0.15) >= 50.0) {
cost = 50.0
} else {
cost = amount * 0.15
}
} else {
if (amount > 75.0) {
cost = 0.0
} else {
cost = 75.0 * 0.1
}
}

return cost

}

fun main(args: Array<String>) {
val total = readLine()!!.toDouble()
val international = readLine()!!.toBoolean()
println(shippingCost(total, international))
}

Answer 1

*I can not pass one test out of five