Question

Each boy in a class has 7 pockets and each girl in that class has 11 pockets. How many boys and how many girls are there in this class if there are 147 pockets and 17 heads?

Answer 1

Answer: There are 10 boys and 7 girls in the class.

Step-by-step explanation:

Let x be the number of boys and y be the number of girls then according to the question we have the following equations :-

$x+y=17...............................(1)\\\\7x+11y=147...........................(2)$

The value of y from (1) will be

$y=17-x$ , substitute this in equation (2), we get

$7x+11(17-x)=147\\\\\Rightarrow\ 7x+187x-11x=147\\\\\Rightarrow\ 187-4x=147\\\\\Rightarrow\ -4x=147-187\\\\\Rightarrow\ -4x=-40\\\\\Rightarrow\ x=10$

∴ $y=17-10=7$

Hence, there are 10 boys and 7 girls in the class.

Answer 2

10 boys equals 70 pockets
7 girls equals 77 pockets

that equals 147 pockets and 17 heads