A heap of stones can be made up into groups of 21. When made up into groups of 16, 20, 25 and 45 there are 3 stones left in each case. How many stones at least can there be in the heap?
Choose the correct choice from the following options:
A) 7203  B) 2403  C) 3603  D) 4803  E) 5803
LCM of 16, 20, 25, 45 = 3600   1 * 3600 + 3= 
<gadget id="calculator">1 * 3600 + 3</gadget>
<output>3_603</output>
3603 not divisible by 21   2 * 3600 + 3= 
<gadget id="calculator">2 * 3600 + 3</gadget>
<output>7_203</output>
7203 is divisible by 21   7203NSWER:7203
<result>A</result>
A heap of stones can be made up into groups of 21. When made up into groups of 16, 20, 25 and 45 there are 3 stones left in each case. How many stones at least can there be in the heap?