FIVE YEARS AGO, DAVID WAS THREE TIMES AS OLD AS JULIA WAS. IN 2 YEA...

Lớp 3 Toán ĐỀ THI TOÁN RSM VÀ IMC DÀNH CHO HỌC SINH LỚP 3 ĐẾN LỚP 8

7. Five years ago, David was three times as old as Julia was. In 2 years, David will be twice as old as Julia will be. How old is David now?