When a physical quantity is obtained by arithmetic combination of measured quantities, certain set of rules are applied. Idea behind those rules is the fact that precision in reporting of derived physical quantity is limited by the physical quantity which has been measured with least precision. Keeping that into mind, which of the following options are CORRECT for the arithmetic operation of measured values  a=130 cm and  b=121.50 cm

In case of addition or subtraction, result must contain as many decimal places as there are in measured value with least number of decimal places.In case of multiplication or division, result must contain as many significant figures as there are in measured value with least number of significant figures.a-b = 130-121.50 = 8.5 = 8 (rounding off to 1 digit)a+b = 130+121.50 = 251.50 = 252 ab=130×121.50=15795=16000 (Two significant figures)