let

x = the cost of one mathematics book

y = the cost of one science book

the price of mathematics book is R60 less that of a science book (R is rupee the currency of India)

x = y - 60

four maths books cost R260 more than two science books

4x = 260 + 2y

by solving the system of equations

x = y - 60

4x = 260 + 2y

we find

x = R190

y = R250

the price of one math book is R190.

the price of one science book is R250.