Explanation

M.P. of an electric Iron = Rs. 690

After Discount, S.P. = 90% of 690 = Rs. 621

Gain = 8%

C.P of an electric Iron = 621×100100+8

= 621×100108= Rs.575

No Discount, gain of Iron = 690 - 575 = Rs. 115

gain % = 115575×100=20

Explanation

A 7% sales tax means:

x + 0.07x = 22.90  

⇒ 1.07x = 22.90  

⇒ x = 22.90 / 1.07 = 21.40

Explanation

Let total money be X

According to the question, we have the equation:

x/6 + x/8 + x/2 + 55 = x

Multiply through by 24 to eliminate the fractions, we get:

4x + 3x + 12x + 1320 = 24x

19x + 1230 = 24x

Subtracting 19x from both sides. 

we have:

1320 = 5x

Dividing both sides by 5, we get:

x = 264