Answer:
The rate of exchange is 8%
Step-by-step explanation:
Given as :
Shelley delivered 12 newspaper after 20 min
And She delivered 36 papers after 60 min
Let the exchange rate = R %
So,
Final value = Initial value × ( 1 +
)
Or, 36 × 60 = 12 × 20 × ( 1 +
)
Or, 2160 = 240 × ( 1 +
)
Or,
= ( 1 +
)
Or, 9 = ( 1 +
)
∴
= 9 -1 = 8
Or , Rate = 8%
Hence The rate of exchange is 8% Answer