The answer is 4 hours
p -<span> the programming time
</span>c - time spent on commercials
<span>A radio station broadcasts programs and commercials 20 hours everyday:
p + c = 20
</span><span>The ratio of the time spent on commercials to the programming time is 1:4.
c : p = 1 : 4
p = c * 4 : 1
p = 4c
p + c = 20
p = 4c
_____
4c + c = 20
5c = 20
c = 20 : 5
c = 4h</span>
Answer:
By comparing the ratios of sides in similar triangles ΔABC and ΔADB,we can say that 
Step-by-step explanation:
Given that ∠ABC=∠ADC, AD=p and DC=q.
Let us take compare Δ ABC and Δ ADB in the attached file , ∠A is common in both triangles
and given ∠ABC=∠ADB=90°
Hence using AA postulate, ΔABC ≈ ΔADB.
Now we will equate respective side ratios in both triangles.

Since we don't know BD , BC let us take first equality and plugin the variables given in respective sides.

Cross multiply

Hence proved.
A.12 because i had same question
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