Question

The cost of making a dress is partly constant and partly varies with the amount of time it takes to make the dress.if the dress takes 3 hours to make the dress,it cost 3100 naira.find the cost if it takes 1.5 hours to make the dress.

Answer 1

To find the cost if it takes 1.5 hours to make the dress, we can use the concept of variation.

Let's denote the constant cost as C and the variable cost per hour as V. We know that when it takes 3 hours to make the dress, the cost is 3100 naira.

So we can set up the equation:
C + V*3 = 3100

Now, we can solve for C by substituting the values and simplifying the equation:

C + V*3 = 3100
C + 3V = 3100

Similarly, when it takes 1.5 hours to make the dress, we can set up the equation:
C + V*1.5 = ?

Since we want to find the cost, we'll use a question mark "?" to represent the unknown value.

Now, we can substitute the values of C and V from the previous equation into this new equation:
(C + 3V)/2 = ?

Substituting the known values from the previous equation:
(3100 + 3V)/2 = ?

Multiplying both sides by 2 to eliminate the denominator:
3100 + 3V = ? * 2
3100 + 3V = 2?

Now we have two equations:
C + 3V = 3100
3100 + 3V = 2?

We can solve these equations to find the values of C and V.