By how much per cent expenditure of company Q and R together is greater than that of company P?

Percentage expenditure of Q and R

= (22 + 18)% = 40%

$herefore$ Required per cent $=left(frac{40-24}{24} ight) imes 100$

$=frac{16}{24} imes 100=frac{200}{3}=66.67 \%$