The ratio of fold to block mountains in D is 3:5 respectively. If the number of fold mountains in A is one-fifth that of in D, then the block mountains in A is what percentage of the total number of fold mountains in A and D together (approx.)?(Note: Mountains are either fold or block)

Read the following bar graph and table carefully and answer the questions given below. The bar graph shows total number of beaches in five different countries. The table shows percentage of mountains out of total beaches and mountains together in these countries.

Countries	Percentage of mountains out of total beaches and mountains together
A	60%
B	75%
C	20%
D	80%
E	50%

The correct answer is 39%.

Step 1: Extract data from the bar graph and table
By analyzing the provided bar graph, we can find the number of beaches in each country using the vertical axis scale (where each grid line represents 10 units):
• Number of beaches in Country A = 100
• Number of beaches in Country D = 150

From the table, the percentage of mountains out of the total beaches and mountains together for Country A and Country D is given as:
• Country A = 60%
• Country D = 80%

Step 2: Calculate the total number of mountains in Country A
Since mountains represent 60% of the total (beaches + mountains) in Country A, the beaches must represent the remaining 40% of the total.
Let the total number of beaches and mountains in Country A be $T_A$.
We have:

$40\%\text{of}{T}_A=100$

$T_A=\frac{100}{0.40}=250$

Thus, the total number of mountains in Country A is:

$\text{Total Mountains in A}=60\%\times 250=150$

Step 3: Calculate the total number of mountains in Country D
In Country D, mountains represent 80% of the total, meaning the beaches represent 20% of the total.
Let the total number of beaches and mountains in Country D be $T_D$.
We have:

$20\%\text{of}{T}_D=150$

$T_D=\frac{150}{0.20}=750$

Thus, the total number of mountains in Country D is:

$\text{Total Mountains in D}=80\%\times 750=600$

Step 4: Determine fold and block mountains in Countries A and D
The ratio of fold to block mountains in Country D is given as 3:5.
Using this ratio, the number of fold mountains in Country D is:

$\text{Fold Mountains in D}=600\times \frac{3}{3+5}=600\times \frac{3}{8}=225$

The number of fold mountains in Country A is one-fifth of that in Country D:

$\text{Fold Mountains in A}=\frac{1}{5}\times 225=45$

Since all mountains are either fold or block, the block mountains in Country A is:

$\text{Block Mountains in A}=\text{Total Mountains in A}-\text{Fold Mountains in A}=150-45=105$

Step 5: Calculate the required percentage
The total number of fold mountains in A and D together is:

$\text{Total Fold Mountains (A + D)}=45+225=270$

The percentage of the block mountains in A out of the total fold mountains in A and D together is:

$\text{Percentage}=\left(\frac{105}{270}\right)\times 100\%=\frac{35}{90}\times 100\%=\frac{350}{9}\%\approx 38.89\%$

This is approximately 39%.