Question

Ученик рассчитывал за 1 5/6 часа приготовить уроки и за 1 3/4ч закончить модель корабля. однако на всё работу он потратил на 2/5 ч меньше, чем предполагал . сколько времени потратил ученик на всё работу? Срочно!!!

Answer 1

1 5/6 + 1 3/4= 1 10/12+1 9/12=2 19/12= 3 7/12
3 7/12 - 2/5= 3 35/60 - 24/60 = 3 11/60

Answer 2

To solve this problem, we need to calculate the total time the student spent on both tasks. Let's break it down step by step.

Step 1: Calculate the time the student planned to spend on each task

The student planned to spend 1 5/6 hours on preparing lessons and 1 3/4 hours on finishing the model ship.

Step 2: Calculate the time the student actually spent on each task

The student spent 2/5 hours less than planned on the total work.

To find the actual time spent on each task, we need to subtract 2/5 hours from the planned time for each task.

For preparing lessons: 1 5/6 hours - 2/5 hours = (5/6 - 2/5) hours

For finishing the model ship: 1 3/4 hours - 2/5 hours = (3/4 - 2/5) hours

Step 3: Calculate the total time spent on both tasks

To find the total time spent, we need to add the actual time spent on preparing lessons and finishing the model ship.

Total time spent = (5/6 - 2/5) hours + (3/4 - 2/5) hours

To add fractions with different denominators, we need to find a common denominator. In this case, the common denominator is 30.

Total time spent = (25/30 - 12/30) hours + (15/30 - 12/30) hours

Simplifying the fractions:

Total time spent = 13/30 hours + 3/30 hours

Total time spent = 16/30 hours

Step 4: Simplify the fraction

To simplify the fraction, we can divide both the numerator and denominator by their greatest common divisor, which is 2.

Total time spent = (16/2) / (30/2) hours

Total time spent = 8/15 hours

Therefore, the student spent 8/15 hours on the total work.

Please note that the above solution is based on the information provided in the question.