Question

Find numbers from $100$ to $400$ that end with $0,1,4,5,6$ or $9$, which are perfect squares.

Answer 1

Following are the perfect squares between $100$ to $400$
${10}^2=100,{11}^2=121$

${12}^2=144,{13}^2=169$

${14}^2=196,{15}^2=225$

${16}^2=256,{17}^2=289$

${18}^2=324,{19}^2=361,{20}^2=400$

All the above numbers ends with either $0,1,4,5,6$ or $9$

Thus, the numbers from $100$ to $400$ that end with $0,1,4,5,6$ or $9$, which are perfect squares are given above.