EXERCISE . . Solve the following systems of linear equations by Cramer’s rule: (i) (ii) (iii) (iv) −= + = . In a competitive examination, one mark is awarded for every correct answer while mark is deducted for every wrong answer.
A student answered questions and got marks. How many questions did he answer correctly ? (Use Cramer’s rule to solve the problem). .
A chemist has one solution which is % acid and another solution which is % acid. How much each should be mixed to make litres of a % acid solution ? (Use Cramer’s rule to solve the problem). .
A fish tank can be filled in minutes using both pumps A and B simultaneously. However, pump B can pump water in or out at the same rate. If pump B is inadvertently run in reverse, then the tank will be filled in minutes. How long would it take each pump to fill the tank by itself ?
(Use Cramer’s rule to solve the problem). - - . A family of people went out for dinner in a restaurant. The cost of two dosai, three idlies and two vadais is ` .
The cost of the two dosai, two idlies and four vadais is ` . The cost of five dosai, four idlies and two vadais is ` . The family has ` in hand and they ate dosai and six idlies and six vadais. Will they be able to manage to pay the bill within the amount they had ?