If 6a = 7b = 20, then 84ab =	Choose one
A) 50
B) 100
C) 625
D) 800
E) 1250
6a * 7b = 20 * 20= 
<gadget id="calculator">20 * 20</gadget>
<output>400</output>
400   42 ab= 400   i.e. 84 ab = 800   Answer: Option 800
<result>D</result>
If 6a = 7b = 20, then 84ab =