Question

Five times the number of test tubes in a school’s chemistry lab exceeds three times the number of beakers it has by 660 The sum of two times the number of test tubes and five times the number of beakers is 450

Answer 1

let the number of test tubes be x
and that of beakers be y
ATQ
$5x - 3y = 660 .....(1) \times 5\\ 2x + 5y = 450.....(2) \times 3\\ we \: get \\ 25x - 15y = 3300 \\ 6x + 15y = 1350\\ = > 31x = 4650 \\ x = \frac{4650}{31} = 150 \\ \\ putting \: the \: value \: of \: x \: in \: \: (2) \\ 2 \times 150 + 5y = 450 \\ 300 + 5y = 450 \\ 5y = 450 - 300 \\ 5y = 150 \\ y = \frac{150}{5} = 30$

no of test tubes=150
no of beakers =30