So let's use some equations to represent the data [let R= cost of ring & B= cost of bracelet]
R= B + $ 36 .... (1)
B=

× R ... (2)
By using simultaneous equations to solve for B and R.
Substitute eq. (1) into eq. (2)
B =

× (B + $36)
B =

B +

⇒ B = $48
By substituting value of B into ea (1)
If R = B + $36
R = ($48) + $36
= $84
∴ <span> the total of the two items = R + B
= $84 + $48
</span> = $132
Answer:
8 of the electrons will be valence electrons
Explanation:
They help keep track of notes and experaments
The mixture contains:
CaCO3 + (NH4)2CO3 in which the amount of carbonate CO3 = 60.7% by mass
Let, the total mass = 100 grams
Mass of CaCO3 = x grams
Mass of (NH4)2CO3 = y grams
Thus, x + y = 100 ------------(1)
Mass of CO3 = 60.7% = 60.7 g
Molar mass of CO3 = 60 g/mol
Total # moles of CO3 = 60.7 g/60 g.mol-1 = 1.012 moles
The total moles of CO3 comes from CaCO3 and (NH4)2CO3. Therefore,
moles CaCO3 + moles (NH4)2CO3 = 1.012
mass CaCO3/molar mass CaCO3 + mass (NH4)2 CO3/molar mass = 1.012
x/100 + y/96 = 1.012---------(2)
based on equation 1 we can write: y = 100-x
x/100 + (100-x)/96 = 1.012
x = 71.2 g
Mass of CaCO3 = 71.2 g