Question

The cost of 3 different varieties of pizzas ar 9, 10 and 12 dollars. Kate father wants to give her money so that she can buy any 1 variety of pizza such that no money is left in the end. What should be least amount he should give her?

• A. 10 dollars
• B. 112 dollars
• C. 75 dollars
• D. 180 dollars

Answer 1

The correct option is D 180 dollars

Given, cost of 3 different varieties of pizzas are 9, 10 and 12 dollars.

To find least amount of money required to purchase any 1 variety without leaving any amount in the end is LCM of 9, 10 and 12.

$\underset{–}{\text{LCM of 9, 10 and 12:}}$

$\begin{array}{cc}2& 9,10,12\\ 3& 9,5,6\\ 3& 3,5,2\\ 5& 1,5,2\\ 2& 1,1,2\\ & 1,1,1\end{array}$

$\therefore$ LCM of 9, 10 and 12 is:
$=2\times 3\times 3\times 5\times 2=180$

Hence, Kate's father has to give her 180 dollars