Question

7 pens cost RS 63 what is the cost of 21 pens​

Answer 1

7P=63 -----(1)

21P=?

LETS FIND COST OF 1 PEN

taking eq(1)

7P=63

P= 63

-------

7

= 63÷7

COST OF 1 PEN = 9

SO NOW TO FIND COST OF 21PEN = 21×9

=Rs.189

Answer 2

Step-by-step explanation:

If 7 pens cost = 63 Rs.

1 pen costs = (63÷7)Rs.

= 9 Rs.

So, the cost of 21 pens = (21×9)Rs.

= 189 Rs.

Hope it will help you.

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