Expand PEC and PEN.

PEN stands for

In a box there are 5 black pens,3 white pens and 4 red pens .In how many pens can 2 black pens , 2 white pens and 2 red pens can be chosen ?

The cost of 6 gel pens and 16 ball pens is Rs. 92/-. What will be the cost of 27 gel pens and 72 ball pens?

At a stationery shop it costs Rs 185 for 4 gel- pens,8 ball-point pens and one marker pen and Rs315 for 7 gel-pens,15 ball-point pens and one marker pen.Then what would be the cost of one gel-pen,one ball-point pen and one marker pen? (a) Rs 45 (b) Rs 55 (c) Rs 60 (d) Rs 70

A shopkeeper has 3 varieties of pens ' A^(prime),\ ' B ' and ' C ' . Meenu purchased 1 pen of each variety for a total of Rs 21. Jeen purchased 4 pens of ' A ' variety, 3 pens of ' B ' variety and 2 pens of ' C ' ariety for Rs 60. While Shikha purchased 6 pens of ' A ' variety, 2 pens of ' B ' variety and 3 pens of ' C ' variety for Rs 70. Using matrix method find the cost of each pen.

A shopkeeper has 3 varieties of pens ‘A’, ‘B’ and ‘C’. Meenu purchased 1 pen of each variety for a total of Rs. 21. Jeevan purchased 4 pens of ‘A’ variety, 3 pens of ‘B’ variety and 2 pens of ‘C’ variety for Rs. 60. While Shikha purchased 6 pens of ‘A’ variety, 2 pens of ‘B’ variety and 3 pens of ‘C’ variety for Rs. 70. Using matrix method, find cost of each variety of pen.

A box contains 40 pens out of which x are non-defective. If one pen is drawn at random, the probability of drawing a non defective pen is y. If we replace the pen drawn and then add 20 more non-defective pens in this bag, the probability of drawing a non-defective pen is 4y. Then, evaluate the value of x.

A box contains 40 pens out of which x are non-defective. If one pen is drawn at random, the probability of drawing a non-defective pen is y. If we replace the pen drawn and then add 20 more non-defective pens in this bag the probability of drawing a non-defective pen is 4y. Then, evaluate the value of x.