Question No. 10.
The radii of two circles are 5 cms and 2 cms. The length of
the direct common tangents to the circles is 1.5 times the
length of the transverse common tangents. The distance
between the centers of the circles in cms
a few seconds with google will provide several discussions of this problem. For example, see
https://www.askiitians.com/iit-jee-coordinate-geometry/common-tangents.aspx