Here, probability of `P` speaking truth, `P(T) = 70% = 7/10`
`:.` probability of `P` speaking lie, `P(L) = 1- 7/10 = 3/10`
Probability of `Q` speaking truth, `Q(T) = 80% = 4/5`
`:.` probability of `Q` speaking lie, `Q(L) = 1- 4/5 = 1/5`
Probability of both `P` and `Q` agree in same fact `P(S) = P(T)nnQ(T) +P(L)nnQ(L)`
As, all these events are indepependent event,
`:. P(S) = P(T)Q(T)+P(L)Q(L)`
`P(S) = 7/10**4/5+3/10**1/5 = 28/50+3/50 = 31/50`
So, percentage of both of them agree on same fact `= 31/50**100 = 62%`
Also, we can clearly see that when both of them agree, they also speak lie
and probability of that is `3/50`.