$Changing\ question:$
$a[0...50,0...50]=a[51][51]$
$loc[45][47]:RMO$
$0^{th}\ row=51(0+x=51)$
$1^{st}\ row=50(1+x=51)$
$2^{nd}\ row=49(2+x=51)$
.
.
.
$44^{th}\ row=7(44+x=51)$
$Sum=51+50+49....+7=1305$
Now you are standing on $45^{th}$ row and it's first element will start from $45^{th}$ column but you need to go to $47^{th}$ column, hence add $3(45,46,47)$
$1305+3=1308$
But index starts from $0,$ so subtract $1$
$1308-1=1307$
$1307\times 100=130700$