Question

60 packets with 8 pencils each cost rs.800. find the cost of 75 packets of 10 pencils each.

Answer 1

Cost of $60$ packets of $8$ pencils $=Rs.800$

Cost of $1$ packet of $8$ pencils $=\frac{800}{60}=Rs.\frac{80}{6}$

Now,

Cost of $8$ pencils $=Rs.\frac{80}{6}$

Cos of $10$ pencil $=\frac{80}{6\times 8}\times 10=Rs.\frac{50}{3}$

Now,

Cost of $1$ packet of $10$ pencils $=Rs.\frac{50}{3}$

Cost of $75$ packets of $10$ pencils $=Rs.\frac{50}{3}\times 75=Rs.1250$

Hence the cost of $75$ packets of $10$ pencils each is $Rs.1250$.