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3/5 of a number is 162. what is the number?

SOLVING ALGEBRAICALLY3/5 of "a number" = 3/5 of "x"3/5 of x is equivalent to (3x)/5(3x)/5 = 162Move the "5" to the other side by multiplying:3x = (162x5) = 810We now have 3x ...

Answered by Fred J. • Maths tutor

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10 The table gives information about the heights of 50 trees. Height (h metres) Frequency 0 < h - 4 ,8, 4 < h - 8 ,21, 8 < h - 12, 12, 12 < h - 16, 7, 16 < h - 20, 2. Work out an estimate for the mean height of the trees.

First find the appropriate mid points of each set of intervals. These will be 2, 6, 10, 14 and 18, and you get these my dividing in two the interval range. Then multiply each midpoint by the correspondin...

Answered by Charlie W. • Maths tutor

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How do I find roots of a quadratic equation when I can't factorise?

When factorising isn't working, we can try using the quadratic formula. First, we need our quadratic equation and find a,b and c - the coefficients of x and the constant. Now, we can wri...

Answered by Freya D. • Maths tutor

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It is given that sin(x) = 1/2. Find the value of sec(x)

x = 30ºcos(30) = √3/2sec(30) = 2/√3 or 2√3/3

Answered by Alex H. • Maths tutor

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A piggy bank contains 200 coins, 1/4 of these are 1p coins, 100 of these are 5p coins and the rest are 10p coins, how much is the piggy bank worth in £s?

The piggy bank contains a total of 200 coins, 1/4 of this is 50, this means the piggy bank must contain 50 1p coins, we can convert this to £s by dividing by 100, which gives us £0.01 which we can times b...

Answered by Henry O. • Maths tutor

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