# Bomb The Target! Part 2

**Discrete Mathematics**Level 5

A **B-2 spirit bomber** is bombing a city. The chance that a bomb dropped by it hits the target is \(50\)**%**.

It requires \(2\) **direct and consecutive** bomb hits to destroy the city. If the bomber drops 7 bombs, then the probability that the city isn't destroyed is \(\dfrac{a}{b}\) where \(a\) and \(b\) are co-prime positive integers.

Find \(a+b\).