$1.$ A company uses the following differential piecework scheme.

Output level pay per unit $($$$)$

Up to $100$ units $$12$

$101-200$ units $$16$

More than $200$ units $$22$

Higher rates are only applicable to additional units produced. Guaranteed minimum wage is $$900$ per week. In the first month John Keynes produced:

Week $1$ Week $2$ Week $3$ Week $4$

$260140340440$

Employees national insurance contribution is $15\%$ of gross pay and employees also pay $25\%$ income tax after deducting national insurance contribution. Employer also pays $20\%$ of gross pay as national insurance contribution on behalf of employee to the government.

$1.$ Calculate gross pay for John Keynes in the first month

$2.$ Calculate amount of money that John Keynes should receive as wages for the month

$3.$ Calculate wages expense for the company