9514 1404 393
Answer:
A. 2.1
Step-by-step explanation:
Put the numbers in the equation and do the arithmetic.
1/R = 1/(3 1/2) +1/(5 1/4)
1/R = 1/(7/2) +1/(21/4) = 2/7 +4/21 = (6 +4)/21
R = 1/(10/21) = 21/10
R = 2.1
