A LAMBDA Exercise

Patrick2788 

As variant

weekdayMultiplier=
LAMBDA( weekday, CHOOSE(weekday, 1.5, 1, 1, 1, 1, 1, 1.5) );

weekdayHours= 
LAMBDA( vector, weekday,
    SCAN(0, vector,
        LAMBDA(a,v,
            IF( v= 4, 16, // with simplified holidays
            IF( v = "", 0,
            IF( ISTEXT(v), a, 8*weekdayMultiplier(weekday)) ) ) ) )
);
weekdayPersonHours=
LAMBDA( vector, weekday, name,
    SUM( weekdayHours(vector, weekday)*(vector=name) ));

monthPersonHours=
LAMBDA( month, name,
        REDUCE(0, SEQUENCE(7), LAMBDA( a,v,
            a + weekdayPersonHours( CHOOSECOLS( month,v), v, name) ))
);

GrossPay=
LAMBDA( month, names, rates,
    SCAN(0, names, LAMBDA(a,v, monthPersonHours(month, v) ) )*
    rates
);