मान A = 10, B = 12, C = 70, D = 5, और E = 7 के लिए पोस्टफिक्स व्यंजक A B C D E × / - + का मान ज्ञात कीजिए:

Given a deque (double-ended queue) containing elements [5, 10, 15, 20] (where 5 is at the front and 20 is at the rear), if element '25' is inserted at the front and then an element is deleted from the rear, what will be the new rear element?

Evaluate the prefix expression: - + a b c + d * e f, given that a = 10, b = 2, c = 5, d = 3, e = 4, and f = 1.