Line 3
since he added which is against the order of opreation rule he was supposed to multiply first then add
again what he was supposed to do is
Line 2:21+5+6(2)
Line 3:21+5+12
you just have to move the decimal point 9 places to the right thats an easy trick to remember 1849900000
Answer:
4.6%.
Step-by-step explanation:
The probability that a can of paint contains contamination(C) is 3.23%
P(C)=3.23%
The probability of a mixing(M) error is 2.4%.
P(M)=2.4%
The probability of both is 1.03%.

We want to determine the probability that a randomly selected can has contamination or a mixing error. i.e. 
In probability theory:

The probability that a randomly selected can has contamination or a mixing error is 4.6%.
Answer:
22 cm
Step-by-step explanation:
Simply count the number of square units of each side, then add them up. (each square unit = 1 cm)
4+4+2+3+2+7
= 22 cm