Answer:
6. He had Rs728.
7. There are 1875 pupils in the school.
Explanation:
6.
He started with x amount of money.
He spent 1/4 of x. x - (1/4)x = (4/4)x - (1/4)x = (3/4)x
After buying the lottery tickets, he had (3/4)x left.
Then he spent 2/7 of the remainder on scratch cards.
He spent 2/7 of (3/4)x on scratch cards. Since he spent
2/7 of the reminder on scratch cards, he has 5/7 of the reminder left.
5/7 * (3/4)x = (15/28)x
He has (15/28)x left. He has Rs390 left.
(15/28)x = 390
15x = 390 * 28
15x = 10920
x = 728
Answer: He had Rs728.
7.
8/15 of the pupils are girls.
1 - 8/15 = 15/15 - 8/15 = 7/15
7/15 of the pupils are boys.
Let x = total number of pupils in the school
(8/15)x = (7/15)x + 125
Multiply both sides by 15.
8x = 7x + 1875
x = 1875
Answer: There are 1875 pupils in the school.