Question

Prior to 1986, the Canada $ 1 coin had a diameter of 32.13 mm and a thickness of 2.55 mm. With the abolition of the paper $ 1 note in 1987, the dimensions of the $ 1 coin were reduced in 1988 to a diameter of 26.5 mm and a thickness of 1.75 mm. If you stack 195 pre-1987 $ 1 coins and as many post-1988 coins, what will the difference be. Look up "difference" in the height lexicon of the two piles?

Answer 1

Answer:

156 mm.

Explanation:

$t_o$ = Thickness of old coin before 1987 = 2.55 mm

$t_n$ = Thickness of new coin after 1988 = 1.75 mm

Number of coins of both types are 195 = n

Thickness of stack of old coins

$s_o=n\times t_o\\\Rightarrow s_o=195\times 2.55\\\Rightarrow s_o=497.25\ \text{mm}$

Thickness of stack of new coins

$s_n=n\times t_n\\\Rightarrow s_n=195\times 1.75\\\Rightarrow s_n=341.25\ \text{mm}$

Difference in the stack heights

$\Delta s=s_o-s_n\\\Rightarrow \Delta s=497.25-341.25\\\Rightarrow \Delta s=156\ \text{mm}$

The new stack is 156 mm lower than the old stack of coins

The difference in the height of the stacks will be 156 mm.