My father is 28 years older than Xiao Liang. Seven years later, my father's age is just three times that of Xiao Liang. How old are my father and Xiao Liang after seven years?

My father is 28 years older than Xiao Liang. Seven years later, my father's age is just three times that of Xiao Liang. How old are my father and Xiao Liang after seven years?

A: seven years later, my father will be 42 years old and Xiao Liang will be 14 years old

Dad is 28 years older than Xiao Liang. Seven years later, Dad's age is just three times that of Xiao Liang. How old are Xiao Liang and Dad this year?

In the title, seven years later, my father's age is exactly three times of Xiaoliang's, so the result of subtracting Xiaoliang's age from my father's age seven years later is two times of Xiaoliang's age. In the title, my father is 28 years older than Xiaoliang this year, so my father is 28 years older than Xiaoliang seven years later, so Xiaoliang's age is 28 △ 2 = 14 (years old), so Xiaoliang's age is 14-7 = 7 (years old), My father is 7 + 28 = 35 this year

81 3——4
Passenger cars and freight cars start from both places at the same time and travel in opposite directions. The passenger cars travel 35 kilometers per hour, which is 5 / 7 of the speed of freight cars. After 3.5 hours, the two cars meet. How many meters is the distance between the two places?
A clothing factory originally planned to use 420 meters of cloth to make 84 sets of clothing. After the improvement, the number of sets was one seventh more than the original. Now, how many meters of cloth do each set use?

1. Because passenger cars are 5 / 7 of the speed of freight cars
So the speed of the truck is 49 km / h
Because we met in 3.5 hours
So the distance between the two places = 3.5 * (35 + 49)
=294km
2. Because the number of sets is one seventh more than the original
So now 420 meters of cloth can make 96 sets
So now each set is 4.375 meters