Question

An over-the-counter multi-vitamin has 350 mg tablets that are 20% calcium by mass. How many tablets are required for you to take a 0.35 g dose of calcium?

Answer 1

.2x350mg = 70mg which converts to .070g.
.35g/.070g = 5 tablets.

Answer 2

Answer:

5  tablets are required for you to take a 0.35 g dose of calcium.

Explanation:

The amount of calcium required = 0.35 g

Percentage of calcium by mass in calcium carbonate = 20%

Total mass of 1 tablet of multi-vitamin =350 mg = 0.35 g

let the number of tablet of multi-vitamin be x

Total mass of tablets = x × 0.35

$\%=\frac{\text{Mass of an element}}{\text{Total mass of tablets}}\times 100$

$20\%=\frac{0.35 g}{x\times 0.350 g}\times 100$

x = 5

5  tablets are required for you to take a 0.35 g dose of calcium.