Answer:
The total amount used is
[tex]294 \: cups[/tex]
Step-by-step explanation:
We were told that 126 cups of plain flour was used, therefore this is saying that
[tex] \frac{3}{7} = 126[/tex]
Recall that from the ratio 4:3, three represents plain four, so 3/7 would be the fraction that depicts plain flour (we add the 4 and 3 to get 7). Since we know the value for plain flour all that is left to do is find the value for wholemeal flour.
[tex] \frac{4}{7} = x[/tex]
4/7 represents the fraction for wholemeal flour, and since we do not know how much he used we will equate it to x. Therefore we know that:
[tex] \frac{3}{7} = 126 \\ \frac{4}{7} = x[/tex]
We now cross multiply:
[tex] \frac{3}{7}( x) = 126( \frac{4}{7}) \\\frac{3}{7} x = \frac{504}{7} \\ \frac{3}{7} x= 72 \\ x = \frac{72}{ \frac{3}{7} } \\ x = 72 \times \frac{7}{3} \\ x= \frac{504}{3} \\ x = 168[/tex]
We add both the values that we got for plain flour and wholemeal flour, this will give us the total amount of flour used.
[tex]168 + 126 = 294[/tex]
