Thanks for all the replies. Actually both the answers are working but i choose the second one and made some changes for my need. Below is the final query
SELECT
(SELECT SUM(Close_price)/200 FROM (SELECT Close_price FROM cash_data WHERE SERIES='$series' AND SYMBOL='$symbol' AND date_added <= '$date' ORDER BY date_added DESC LIMIT 0,200) as tot200) as avg200,
(SELECT SUM(Close_price)/100 FROM (SELECT Close_price FROM cash_data WHERE SERIES='$series' AND SYMBOL='$symbol' AND date_added <= '$date' ORDER BY date_added DESC LIMIT 0,100) as tot100) as avg100,
(SELECT SUM(Close_price)/50 FROM (SELECT Close_price FROM cash_data WHERE SERIES='$series' AND SYMBOL='$symbol' AND date_added <= '$date' ORDER BY date_added DESC LIMIT 0,50) as tot50) as avg50
Thank you all.