A trader bought x mangoes at the rate of 4 mangoes for 10 naira, five of the mangoes were bad so he sold the remaining at the rate of 5 mangoes for 20 naira and he made a gain of 10 naira how many mangoes did he buy?

  20

Step-by-step explanation:

The cost of the x mangoes was ...

  c = 10(x/4)

The revenue from the sale of mangoes was ...

  r = 20(x-5)/5

The profit is the difference between revenue and cost:

  10 = r - c = 20(x -5)/5 -10(x/4) = 1.5x -20 . . . . substitute and simplify

  30 = 1.5x . . . . . add 20

  20 = x . . . . . . . .divide by 1.5

The trader bought 20 mangoes.

Check

He paid 20(10/4) = 50 naira. He sold the 15 good mangoes for 20/5(15) = 60 naira, so made a 10 naira profit.

spinning a 1, 2, or 3. option d.

step-by-step explanation: when spinning a number graph up to 4, and aiming for any number less than 3, that automatically eliminates the number 4. now you have two numbers to spin on that are less than 3, but the number 3 is included in this question because it's no greater of an number than itself. i hope this you : )

all it means is function 3