Question (iv) - Digits in Disguise - Chapter 5 Class 8 - Number Play (Ganita Prakash)

Transcript

Question (iv) – Page 131 This is the same as writing 𝑄𝑅 × 3=𝑃𝑅𝑅 Now, 3 × 𝑅 ends in 𝑅. This only happens if 𝐑=𝟎 or 𝐑=𝟓. Let’s try both If 𝑹=𝟎: 𝑄0×3=𝑃00 This is impossible, as no value of Q will give two zero’s at the end If 𝑹=𝟓: Units Column 3 × 5=15 (carry 1 ). Tens column: (3 × 𝑄)+1 must end in 𝑅 (which is 5). So, 3 × 𝑄 must end in 4. Thus, Q can be 8 as 3 × 8=24 Check: 𝟖𝟓 × 𝟑=𝟐𝟓𝟓 Thus, our answer is 𝐐=𝟖,𝐑=𝟓,𝐏=𝟐