3. A ball and a bat cost $£ 90$ in total. Three balls and two bats cost $£ 210$ in total. How much does a bat cost?
A $£ 20$
B $£ 30$
C $£ 40$
$\mathrm{D} £ 50$
E $£ 60$
3. E Since one ball and one bat cost $£ 90$, two balls and two bats cost $2 \times £ 90=£ 180$. Now, since three balls and two bats cost $£ 210$, one ball costs $£ 210-£ 180=£ 30$. Therefore a bat costs $£ 90-£ 30=£ 60$.