this is for chem please answer ASAP you have 1 hour.

Report the answers of these calculations to the correct number of significant figures:

(a) 5.062 x 3.64650 x 2.6805 = ?

(b) 11.4129 + 15.5928 + 8.929 = ?

(c) (1.4497 x 1010)(3.539 x 10-19) /6.6 = ? (Report answer in exponential notation.)

If PV = [gR(T+273.15)]/M, solve for M when P = 333, V = 0.244, g = 0.314, R = 62.37, and T = 35.

A sheet of metal is 54.6 mm wide and 23.7 mm long. If it weighs 5.719 g and the density of the metal is 19.3 g/cm3 , what is the thickness of the sheet (in mm)?