Actuarial Science help: Survival Models

Could somebody please help me with the following problems:

Let X1 and X2 be independent random variables. Define the variables Y =min(X1,X2) and Z = max(X1,X2).

a) Show that Sy(y) is the product of the survival distribution functions of X1 and X2.

b) Show that Fz(z) is the cumulative distribution functions of X1 and X2.

c)Show that if X1 and X2 both have exponential distributions, then Y also has an exponential distribution, but Z does not.

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Let the independent random variables X1 and X2 both have exponential distributions, with parameters lambda1 and lambda2 respectively, where lambda1>lambda2. Let Y =min(X1,X2) and Z =max(X1,X2). Given that

Sy(2) = 0.24 and Sz(2) = 0.86, find the value of lambda1.