Write the equality and two conversion factors, and identify the numbers as exact or give the number of significant figures for each of the following:
a. The Daily Value (DV) for iodine is $150mcg$
b. Gold jewelry contains $58\%$ gold by mass.
c. The price of a liter of milk is $\$1.65$
d. A metric ton is $1000kg$

We are given that the Daily Value (DV) for iodine is $150mcg$

According to given information

Equality is$1DV=150mcg$

Two conversion factors are$\frac{1DV}{150mcg},\frac{150mcg}{1DV}$

There are two significant and one exact numbers.

We are given that Gold jewelry contains $58\%$gold by mass.

According to given information

Equality is$100goldjewelry=58gold$

Two conversion factors are $\frac{58}{100},\frac{100}{58}$

There are two significant and one exact numbers.

We are given that The price of a liter of milk is$\$1.65$

According to given information

Equality is$1L=\$1.65$

Two conversion factors are$\frac{1L}{\$1.65},\frac{\$1.65}{1L}$

There are three significant and one exact numbers.

We are given that a metric ton is $1000kg$

According to given information

Equality is$1metricton=1000kg$

Two conversion factors are $\frac{1metricton}{1000kg},\frac{1000kg}{1metricton}$

There are one significant and one exact numbers.