Question 585034
How much money did Ann need to buy 30 pens?
If each one is Rs 4.50, she needed 
{{{ 30*4.5 = 135 }}} = Rs 135
Imagine that she has the Rs 135 in her hand
and hasn't bought anything yet.
For every Rs 5 in her hand, she can buy 3 pencils
135 divided by 5 is 27. So, 27 is how many times
she can buy 3 pencils.
3 pencils times 27 = 81 pencils
Hope this helps