Question

a boy is 5 years old and his sister is 3 times as old as he is when the boy is 10, how old will his siter be

Answer 1

i get 30

Answer 2

If the boy is 5, and the sister is 3 times as old, then she is 5 x 3 = 15 years old. The boy will be 10 in 5 years, and she will be 15 + 5 = 20 years old in 5 years.

Answer 3

It's given that boy's age is 5
When the boy's age is 10, it's given that his sister's age is thrice of his age, that is his sister's age is 30 when his age is 10
so his sister is 20 years older than him,
so what's his sister's present age?

Answer 4

so she is 30 when he is 10 ?

Answer 5

Yeah, it's given in the problem that her age is thrice of the boy's age when he is 10.
Tell me what's her present age

Answer 6

yes she will be 30 when boy is 10. So the when the boy was 5 years old(so we subtracted 5 years from boy's age which is 10), sister will be 25(we also subtract sister's age 30 by 5 to get 25) not 20.

Answer 7

15

Answer 8

is this question:
1) "A boy is 5 years old and his sister is 3 times as old as he is. When the boy is 10, how old will his sister be?"

or:
2) "A boy is 5 years old and his sister is 3 times as old as he is when the boy is 10. How old will his sister be?"

Answer 9

it matters where the full stop is

Answer 10

yes is that the question? as asnaseer said?

Answer 11

which one (1) or (2)?

Answer 12

if its 2 answer is 25 and if its the 1 it'll be 20

Answer 13

(1) seems to make more sense grammatically, in which case beans1992 is correct.

Answer 14

yes it is question 1

Answer 15

but i thought she would be 30

Answer 16

5x3=30

Answer 17

look at the explanation given by beans1992.

Answer 18

i mean 10x3=30

Answer 19

the sister was only 3 times his age when the boy was 5 years old.
so, when the boy was 5, his sister must have been 5*3 = 15 years old.

now imagine one year passes by, the boy becomes 6, and his sister becomes 16.
similarly, if 5 years pass by, then the boy becomes 10, and his sister becomes 20.

Answer 20

got it!! i understand now thanks

Answer 21

yw