Error Price Set Calculation

Step
Go to
Home >> Civicrm >> Administrator civicrm >> Price Set

Create Price set With name ****
Create Price Field with Following sequence..
First Field
Input Field Type is Radio with two options
Label Value
Radio one 100
Radio two 200

Second Field in same price set group
Input Field Type is Checkbox with two options
Label Value
CheckBox one 50
CheckBox two 150

Now select this price set in online event registration

In Registration select value from Radio Field '$100'
and from checkbox Field '$50'

On confirmation page you see total value is $250 instead of $150