Câu số 43: Think of a number that if you add 720 to it the answer will be 1427. The number is………… Câu số 44: The average of age of mother and daughter is 21 years. Mother is 24 years older than daughter. Mother is ………..years old. Câu số 45: Calculate: (12639 + 21034) × 2 = ……… Câu số 46: The average of 3, 4 and 8 is……………… Câu số 47: Edward earns 20 dollars each hour. He will earn …..dollars in 8 hours. Câu số 48: If 77 : a = 7 then a = ………….. 5 sao