exam plus 2 maths question

[Sulikhan]

hi
i would be grateful if someone could explain the following questions
1)Arya rings every multiple of 13 less than 500.She then crosses every multiple of 17 less than 500.How many numbers get both ringed and crossed?
answer =2


2)A clock says 10:00, If the clock is wound on so the minute hand passes through 1800 degree, through how many degrees does the hour hand pass?
answer = 150

[solimum]

1) - it's asking for numbers which are multiples of both 13 and 17 under 500

13 and 17 are prime numbers so any numbers which are multiples of both must be multiples of 13 x 17 (which is 221)

We can have 221, then 442, then any further multiples would be too big - so there are only 2 possible answers



2) on a clock when the minute hand goes round by 360 degrees - a full circle - the hour hand has advanced one hour. As there are 12 hours on the clock face the angle moved for one hour is (360 divided by 12) 30 degrees.

1800 degrees is 5 complete rotations so the hour hand would advance 5 hours, so an angle of 5 x 30 = 150 degrees

Try to find a visual aid for this - either a real clock with hands or an online animation - as children nowadays seem to find clocks difficult.

[Sulikhan]

wow!!! I am very impressed. You are very good.

thank you so much

[Choccy74]

I had to re-read these questions a couple of times to understand them, and the OP obviously needed help with them; how does the average ten year old taking the 11+ exam, with the added time pressure, stand a chance?

[Surferfish]

hi
i would be grateful if someone could explain the following questions
1)Arya rings every multiple of 13 less than 500.She then crosses every multiple of 17 less than 500.How many numbers get both ringed and crossed?
answer =2


2)A clock says 10:00, If the clock is wound on so the minute hand passes through 1800 degree, through how many degrees does the hour hand pass?
answer = 150

Great explanations by solimum so nothing to add, other than to ask since when did 11+ questions start including Game of Thrones characters in them?!