36. Refer to Fig. 35-17. For the intermediate image p =10 mmandi =(fob+s+fey)-fey = 300 m-50 mm =
250 mm, so
1 1 1 1 1
= + = + =Ò! fob =9.62 mm ,
fob i p 250 mm 10 mm
and s =(fob + s + fey) - fob - fey = 300 mm - 9.62 mm - 50 mm = 240 mm. Then from Eq. 35-14,

s 25 cm 240 mm 150 mm
M = - = - = -125 .
fob fey 9.62 mm 50 mm