need clarification

Let the cost of a mango be x. Reduced price is 4/5 x. (i.e. 0.8 x)

(40/0.8 x) - (40/x) = 25
10/x = 25
x = 10/25 = 2/5
Cost of 200 mangoes at reduced price of 4/5x = 4/5 * 2/5 * 200 = 64.
IMO D

Let x be the price of a mango and y be the number of mangoes.

Original Price ==> x * y = 40 .... (1)

Reduced Price ==> 0.8x * (y+25) = 40

20x + 0.8xy = 40 ........ (2)

Sub (1) in (2),

20x + 32 = 40
20x = 8
x = 2/5

Sub x in (1) to find y,
y = 100

So, original price per mango is 2/5. Reduced price per mango is 2/5 * 0.8 = 8/25.

The reduced price of the basket that contains 200 mangoes = 8/25 * 200 = 64 (D)