17,900 x 0.1296 = 2318.05
2318.05 should be subtracted from 17,900 and it should be somewhere around 15,581.95
I would do it in Buhh I'm working so add all of them(16,18,20) together 6 times then add another 16 and 18 and you will get your answer.
Answer:
since the unknown amount can buy 100 pencils
he bought 70 pencils
therefore $4.50 can buy 30 pencils
so 1 pencils cost $4.50 /30=0.15
(49)(58) = 2,842
49
x58
------
2,842
