L need detailed answer basicly solution manuel answer is 145,8

An insulating solid sphere of Radius RI=IO cm with its uniform total charge of +8.8 C is put inside another insulating spherical shell of outer radius Rr 20 cm. The spherical shell region between RI and R2 contains total charge of qr-ql C which spreads over the region between RI and R2 uniformly. Find the magnitude of the electric field at the point r=16.5 cm away from the common center of both spheres by using the Gauss's Law. (Your result must be in multiples of 1010 N/C. That 10 means if, for example, you get a result of 9.22 x 10 just type 9.22 in the answer box. Include 1 digit after the decimal point and maximum of 2% of error is accepted in your answer. Take k=9x109. ) 145.78