Which two expressions each represent 3/21 ?

A) 3⟌21 and 21 ÷ 3

B) 3⟌21 and 3 ÷ 21

C) 21⟌3 and 3 ÷ 21

D) 21⟌3 and 21 ÷ 3
Please help!

What is the simplified form of (3.25x10^3)(7.8x10^6) written in scientific notation?

The scatterplot below shows the number of hours that students read weekly and the number of hours that they spend on chores weekly. which statement about the scatterplot is true?

If m∠abc = 70°, what is m∠abd? justify your reasoning.  using the addition property of equality, 40 + 70 = 110, so m∠abd = 110°.  using the subtraction property of equality, 70 − 30 = 40, so m∠abd = 30°.  using the angle addition postulate, 40 + m∠abd = 70. so, m∠abd = 30° using the subtraction property of equality.  using the angle addition postulate, 40 + 70 = m∠abd. so, m∠abd = 110° using the addition property of equality.