15.1. When dividing the number $M$ by 54, the quotient is $q$ and the remainder is 37. What will be the quotient and the remainder when dividing the number $M$ by 18?

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(6-7 \text { th) }
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15.1. We have $M=54 q+37=18 \cdot 3 q+18 \cdot 2+1=18(3 q+2)+1$. Thus, when the number $M$ is divided by 18, the quotient will be $3 q+2$ and the remainder will be 1.