1. ## Ratio, radius and algebra

Question 1:
two girls share £24.80 in the ratio of 3:5
work out the difference between the larger share and the smaller share.

Question 2:
A circle has a radius of 5cm.

Work out the area of the circle

Question 3:
Ruth says that 7x + 2x - 5 is an equation
ruth is wrong, explain why.

thanks in advance, if you explain how you do the question aswell that would be appreciated.

2. Originally Posted by jedsterg
Question 1:
two girls share £24.80 in the ratio of 3:5
work out the difference between the larger share and the smaller share.
Divide the money into (3+5) parts. Then the larger part of the money is $\displaystyle \frac58 \cdot 24.80$ and the smaller part is $\displaystyle \frac38 \cdot 24.80$.

$\displaystyle \frac58 \cdot 24.80 - \frac38 \cdot 24.80 = 24.80 \left(\frac58 - \frac38\right) = \frac14 \cdot 24.80 = 6.20$
Question 2:
A circle has a radius of 5cm.

Work out the area of the circle
Use the formula to calculate the area of a circle: $\displaystyle a = \pi r^2$
With your question the unit of the area is $\displaystyle cm \cdot cm = cm^2$